From 32423032c3f25b810f0a3c80fe184f3a357cd8a0 Mon Sep 17 00:00:00 2001
From: Julien Rouhaud <julien.rouhaud@free.fr>
Date: Sat, 4 Jun 2022 01:50:14 +0800
Subject: [PATCH v2 1/4] WIP: Rename attnum to attphysnum

This is the bare minimum to make the code compile, a lot more effort is
required for a proper patch.

A lot of things would need to be renamed accordingly, for instance
attnameAttNum() and similar, and a lot of variables name attnums, pk_attnums
and so on.

Author: Julien Rouhaud
Reviewed-by: FIXME
Discussion: FIXME
---
 contrib/amcheck/amcheck--1.2--1.3.sql         |   2 +-
 contrib/amcheck/expected/check_heap.out       |  92 ++---
 contrib/amcheck/verify_heapam.c               |  30 +-
 contrib/amcheck/verify_nbtree.c               |   2 +-
 contrib/dblink/dblink.c                       |  14 +-
 contrib/file_fdw/file_fdw.c                   |  22 +-
 contrib/lo/lo.c                               |  14 +-
 contrib/pageinspect/expected/brin.out         |   8 +-
 contrib/pageinspect/pageinspect--1.2--1.3.sql |   2 +-
 contrib/pageinspect/pageinspect--1.5.sql      |   2 +-
 contrib/pageinspect/pageinspect--1.8--1.9.sql |   2 +-
 contrib/pageinspect/sql/brin.sql              |   2 +-
 contrib/postgres_fdw/deparse.c                |  22 +-
 contrib/postgres_fdw/postgres_fdw.c           |  38 +-
 contrib/sepgsql/dml.c                         |  10 +-
 contrib/sepgsql/label.c                       |   2 +-
 contrib/sepgsql/relation.c                    |  32 +-
 contrib/sepgsql/sepgsql.h                     |   8 +-
 contrib/spi/autoinc.c                         |  10 +-
 contrib/spi/insert_username.c                 |  10 +-
 contrib/spi/moddatetime.c                     |  10 +-
 contrib/test_decoding/test_decoding.c         |   2 +-
 contrib/vacuumlo/vacuumlo.c                   |   2 +-
 doc/src/sgml/amcheck.sgml                     |   4 +-
 doc/src/sgml/fdwhandler.sgml                  |   2 +-
 doc/src/sgml/pageinspect.sgml                 |   4 +-
 doc/src/sgml/ref/psql-ref.sgml                |   2 +-
 doc/src/sgml/sources.sgml                     |   2 +-
 doc/src/sgml/trigger.sgml                     |   2 +-
 doc/src/sgml/xaggr.sgml                       |   4 +-
 src/backend/access/brin/brin_tuple.c          |  18 +-
 src/backend/access/common/attmap.c            |   2 +-
 src/backend/access/common/heaptuple.c         | 108 +++---
 src/backend/access/common/indextuple.c        |  36 +-
 src/backend/access/common/printsimple.c       |   2 +-
 src/backend/access/common/tupdesc.c           |  30 +-
 src/backend/access/gin/ginbulk.c              |  24 +-
 src/backend/access/gin/ginentrypage.c         |  30 +-
 src/backend/access/gin/ginfast.c              |  18 +-
 src/backend/access/gin/ginget.c               |  42 +--
 src/backend/access/gin/gininsert.c            |  46 +--
 src/backend/access/gin/ginlogic.c             |  10 +-
 src/backend/access/gin/ginscan.c              |  22 +-
 src/backend/access/gin/ginutil.c              |  16 +-
 src/backend/access/gin/ginvacuum.c            |   6 +-
 src/backend/access/index/genam.c              |   8 +-
 src/backend/access/index/indexam.c            |  20 +-
 src/backend/access/nbtree/nbtutils.c          |  14 +-
 src/backend/bootstrap/bootstrap.c             |  78 ++--
 src/backend/catalog/aclchk.c                  |  70 ++--
 src/backend/catalog/catalog.c                 |   2 +-
 src/backend/catalog/genbki.pl                 |  20 +-
 src/backend/catalog/heap.c                    |  76 ++--
 src/backend/catalog/index.c                   |  18 +-
 src/backend/catalog/indexing.c                |   6 +-
 src/backend/catalog/information_schema.sql    |  68 ++--
 src/backend/catalog/objectaddress.c           |  24 +-
 src/backend/catalog/pg_attrdef.c              |  32 +-
 src/backend/catalog/pg_depend.c               |  12 +-
 src/backend/catalog/pg_publication.c          |  14 +-
 src/backend/catalog/system_views.sql          |  18 +-
 src/backend/commands/analyze.c                |  28 +-
 src/backend/commands/copy.c                   |  12 +-
 src/backend/commands/copyfrom.c               |  42 +--
 src/backend/commands/copyfromparse.c          |  12 +-
 src/backend/commands/copyto.c                 |  46 +--
 src/backend/commands/createas.c               |   6 +-
 src/backend/commands/event_trigger.c          |  14 +-
 src/backend/commands/indexcmds.c              |   2 +-
 src/backend/commands/matview.c                |  12 +-
 src/backend/commands/publicationcmds.c        |  22 +-
 src/backend/commands/sequence.c               |  10 +-
 src/backend/commands/statscmds.c              |   8 +-
 src/backend/commands/tablecmds.c              | 342 +++++++++---------
 src/backend/commands/trigger.c                |  10 +-
 src/backend/commands/tsearchcmds.c            |  16 +-
 src/backend/commands/typecmds.c               |  16 +-
 src/backend/executor/execExpr.c               |  52 +--
 src/backend/executor/execExprInterp.c         | 110 +++---
 src/backend/executor/execMain.c               |   4 +-
 src/backend/executor/execPartition.c          |   6 +-
 src/backend/executor/execTuples.c             |  52 +--
 src/backend/executor/execUtils.c              |   2 +-
 src/backend/executor/nodeAgg.c                |  12 +-
 src/backend/executor/spi.c                    |  14 +-
 src/backend/foreign/foreign.c                 |  10 +-
 src/backend/jit/llvm/llvmjit_deform.c         | 104 +++---
 src/backend/jit/llvm/llvmjit_expr.c           |   4 +-
 src/backend/optimizer/util/appendinfo.c       |   2 +-
 src/backend/parser/analyze.c                  |   6 +-
 src/backend/parser/parse_clause.c             |  16 +-
 src/backend/parser/parse_relation.c           | 122 +++----
 src/backend/parser/parse_target.c             |  52 +--
 src/backend/parser/parse_type.c               |   8 +-
 src/backend/parser/parse_utilcmd.c            |  64 ++--
 src/backend/replication/basebackup_copy.c     |   6 +-
 src/backend/replication/logical/proto.c       |  14 +-
 src/backend/replication/logical/relation.c    |  20 +-
 .../replication/logical/reorderbuffer.c       |   2 +-
 src/backend/replication/logical/tablesync.c   |  14 +-
 src/backend/replication/logical/worker.c      |  20 +-
 src/backend/replication/pgoutput/pgoutput.c   |   2 +-
 src/backend/replication/walsender.c           |   4 +-
 src/backend/statistics/dependencies.c         | 116 +++---
 src/backend/statistics/extended_stats.c       |  40 +-
 src/backend/statistics/mvdistinct.c           |   4 +-
 src/backend/utils/adt/acl.c                   |  34 +-
 src/backend/utils/adt/expandedrecord.c        |   4 +-
 src/backend/utils/adt/misc.c                  |   6 +-
 src/backend/utils/adt/ri_triggers.c           |   6 +-
 src/backend/utils/adt/ruleutils.c             |  90 ++---
 src/backend/utils/adt/selfuncs.c              |  60 +--
 src/backend/utils/cache/attoptcache.c         |  16 +-
 src/backend/utils/cache/catcache.c            |  10 +-
 src/backend/utils/cache/lsyscache.c           |  58 +--
 src/backend/utils/cache/relcache.c            |  42 +--
 src/backend/utils/cache/syscache.c            |  18 +-
 src/bin/initdb/initdb.c                       |   2 +-
 src/bin/pg_amcheck/pg_amcheck.c               |   4 +-
 src/bin/pg_amcheck/t/003_check.pl             |   2 +-
 src/bin/pg_dump/pg_dump.c                     |  26 +-
 src/bin/psql/describe.c                       | 158 ++++++--
 src/bin/psql/tab-complete.c                   |   4 +-
 src/include/access/genam.h                    |   6 +-
 src/include/access/gin_private.h              |  24 +-
 src/include/access/htup_details.h             |  36 +-
 src/include/access/itup.h                     |  18 +-
 src/include/bootstrap/bootstrap.h             |   2 +-
 src/include/catalog/dependency.h              |   2 +-
 src/include/catalog/heap.h                    |   8 +-
 src/include/catalog/pg_attrdef.h              |  10 +-
 src/include/catalog/pg_attribute.h            |   8 +-
 src/include/catalog/pg_constraint.h           |   4 +-
 src/include/catalog/pg_index.h                |   2 +-
 src/include/catalog/pg_partitioned_table.h    |   2 +-
 src/include/catalog/pg_statistic.h            |   2 +-
 src/include/catalog/pg_statistic_ext.h        |   2 +-
 src/include/catalog/pg_trigger.h              |   2 +-
 src/include/executor/execExpr.h               |   6 +-
 src/include/executor/spi.h                    |   2 +-
 src/include/executor/tuptable.h               |  42 +--
 src/include/foreign/foreign.h                 |   2 +-
 src/include/parser/parsetree.h                |   4 +-
 src/include/utils/acl.h                       |   8 +-
 src/include/utils/attoptcache.h               |   2 +-
 src/include/utils/lsyscache.h                 |  18 +-
 src/include/utils/relcache.h                  |   2 +-
 src/include/utils/selfuncs.h                  |   2 +-
 src/include/utils/syscache.h                  |   6 +-
 src/pl/plpgsql/src/plpgsql.h                  |   2 +-
 ...summarization-and-inprogress-insertion.out |  28 +-
 .../test_misc/t/001_constraint_validation.pl  |   2 +-
 src/test/regress/expected/alter_table.out     |  32 +-
 src/test/regress/expected/create_index.out    |  14 +-
 src/test/regress/expected/create_table.out    |   4 +-
 src/test/regress/expected/create_type.out     |   2 +-
 src/test/regress/expected/foreign_key.out     |   2 +-
 src/test/regress/expected/indexing.out        |  48 +--
 src/test/regress/expected/inherit.out         |   2 +-
 src/test/regress/expected/insert.out          |  14 +-
 src/test/regress/expected/join.out            |   4 +-
 src/test/regress/expected/oidjoins.out        |  16 +-
 src/test/regress/expected/opr_sanity.out      |   4 +-
 src/test/regress/expected/psql.out            |   4 +-
 src/test/regress/expected/rules.out           |  18 +-
 src/test/regress/expected/sanity_check.out    |   6 +-
 src/test/regress/expected/type_sanity.out     |  10 +-
 src/test/regress/regress.c                    |  30 +-
 src/test/regress/sql/alter_table.sql          |  22 +-
 src/test/regress/sql/create_index.sql         |   4 +-
 src/test/regress/sql/create_table.sql         |   4 +-
 src/test/regress/sql/create_type.sql          |   2 +-
 src/test/regress/sql/foreign_key.sql          |   2 +-
 src/test/regress/sql/indexing.sql             |  12 +-
 src/test/regress/sql/inherit.sql              |   2 +-
 src/test/regress/sql/insert.sql               |   4 +-
 src/test/regress/sql/join.sql                 |   4 +-
 src/test/regress/sql/opr_sanity.sql           |   4 +-
 src/test/regress/sql/psql.sql                 |   4 +-
 src/test/regress/sql/sanity_check.sql         |   6 +-
 src/test/regress/sql/type_sanity.sql          |  10 +-
 src/tutorial/syscat.source                    |   4 +-
 182 files changed, 1959 insertions(+), 1857 deletions(-)

diff --git a/contrib/amcheck/amcheck--1.2--1.3.sql b/contrib/amcheck/amcheck--1.2--1.3.sql
index 7237ab738c..5c49ddde17 100644
--- a/contrib/amcheck/amcheck--1.2--1.3.sql
+++ b/contrib/amcheck/amcheck--1.2--1.3.sql
@@ -14,7 +14,7 @@ CREATE FUNCTION verify_heapam(relation regclass,
 							  endblock bigint default null,
 							  blkno OUT bigint,
 							  offnum OUT integer,
-							  attnum OUT integer,
+							  attphysnum OUT integer,
 							  msg OUT text)
 RETURNS SETOF record
 AS 'MODULE_PATHNAME', 'verify_heapam'
diff --git a/contrib/amcheck/expected/check_heap.out b/contrib/amcheck/expected/check_heap.out
index c010361025..d8267d0578 100644
--- a/contrib/amcheck/expected/check_heap.out
+++ b/contrib/amcheck/expected/check_heap.out
@@ -6,60 +6,60 @@ ERROR:  invalid skip option
 HINT:  Valid skip options are "all-visible", "all-frozen", and "none".
 -- Check specifying invalid block ranges when verifying an empty table
 SELECT * FROM verify_heapam(relation := 'heaptest', startblock := 0, endblock := 0);
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', startblock := 5, endblock := 8);
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 -- Check that valid options are not rejected nor corruption reported
 -- for an empty table, and that skip enum-like parameter is case-insensitive
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'none');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'all-frozen');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'all-visible');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'None');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'All-Frozen');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'All-Visible');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'NONE');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'ALL-FROZEN');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'ALL-VISIBLE');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 -- Add some data so subsequent tests are not entirely trivial
@@ -69,23 +69,23 @@ INSERT INTO heaptest (a, b)
 -- Check that valid options are not rejected nor corruption reported
 -- for a non-empty table
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'none');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'all-frozen');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'all-visible');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', startblock := 0, endblock := 0);
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 CREATE ROLE regress_heaptest_role;
@@ -98,8 +98,8 @@ GRANT EXECUTE ON FUNCTION verify_heapam(regclass, boolean, boolean, text, bigint
 -- verify permissions are now sufficient
 SET ROLE regress_heaptest_role;
 SELECT * FROM verify_heapam(relation := 'heaptest');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 RESET ROLE;
@@ -113,23 +113,23 @@ VACUUM (FREEZE, DISABLE_PAGE_SKIPPING) heaptest;
 -- Check that valid options are not rejected nor corruption reported
 -- for a non-empty frozen table
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'none');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'all-frozen');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', skip := 'all-visible');
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 SELECT * FROM verify_heapam(relation := 'heaptest', startblock := 0, endblock := 0);
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 -- Check that partitioned tables (the parent ones) which don't have visibility
@@ -147,8 +147,8 @@ CREATE TABLE test_partition partition OF test_partitioned FOR VALUES IN (1);
 SELECT * FROM verify_heapam('test_partition',
 							startblock := NULL,
 							endblock := NULL);
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 -- Check that valid options are not rejected nor corruption reported
@@ -157,8 +157,8 @@ INSERT INTO test_partitioned (a) (SELECT 1 FROM generate_series(1,1000) gs);
 SELECT * FROM verify_heapam('test_partition',
 							startblock := NULL,
 							endblock := NULL);
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 -- Check that indexes are rejected
@@ -180,8 +180,8 @@ CREATE SEQUENCE test_sequence;
 SELECT * FROM verify_heapam('test_sequence',
 							startblock := NULL,
 							endblock := NULL);
- blkno | offnum | attnum | msg 
--------+--------+--------+-----
+ blkno | offnum | attphysnum | msg 
+-------+--------+------------+-----
 (0 rows)
 
 -- Check that foreign tables are rejected
diff --git a/contrib/amcheck/verify_heapam.c b/contrib/amcheck/verify_heapam.c
index e488f5e234..89d69ab394 100644
--- a/contrib/amcheck/verify_heapam.c
+++ b/contrib/amcheck/verify_heapam.c
@@ -71,7 +71,7 @@ typedef struct ToastedAttribute
 	struct varatt_external toast_pointer;
 	BlockNumber blkno;			/* block in main table */
 	OffsetNumber offnum;		/* offset in main table */
-	AttrNumber	attnum;			/* attribute in main table */
+	AttrNumber	attphysnum;			/* attribute in main table */
 } ToastedAttribute;
 
 /*
@@ -130,7 +130,7 @@ typedef struct HeapCheckContext
 
 	/* Values for iterating over attributes within the tuple */
 	uint32		offset;			/* offset in tuple data */
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 
 	/* True if tuple's xmax makes it eligible for pruning */
 	bool		tuple_could_be_pruned;
@@ -272,10 +272,10 @@ verify_heapam(PG_FUNCTION_ARGS)
 
 	/*
 	 * If we report corruption when not examining some individual attribute,
-	 * we need attnum to be reported as NULL.  Set that up before any
+	 * we need attphysnum to be reported as NULL.  Set that up before any
 	 * corruption reporting might happen.
 	 */
-	ctx.attnum = -1;
+	ctx.attphysnum = -1;
 
 	/* Construct the tuplestore and tuple descriptor */
 	SetSingleFuncCall(fcinfo, 0);
@@ -552,7 +552,7 @@ verify_heapam(PG_FUNCTION_ARGS)
 static void
 report_corruption_internal(Tuplestorestate *tupstore, TupleDesc tupdesc,
 						   BlockNumber blkno, OffsetNumber offnum,
-						   AttrNumber attnum, char *msg)
+						   AttrNumber attphysnum, char *msg)
 {
 	Datum		values[HEAPCHECK_RELATION_COLS];
 	bool		nulls[HEAPCHECK_RELATION_COLS];
@@ -562,8 +562,8 @@ report_corruption_internal(Tuplestorestate *tupstore, TupleDesc tupdesc,
 	MemSet(nulls, 0, sizeof(nulls));
 	values[0] = Int64GetDatum(blkno);
 	values[1] = Int32GetDatum(offnum);
-	values[2] = Int32GetDatum(attnum);
-	nulls[2] = (attnum < 0);
+	values[2] = Int32GetDatum(attphysnum);
+	nulls[2] = (attphysnum < 0);
 	values[3] = CStringGetTextDatum(msg);
 
 	/*
@@ -591,7 +591,7 @@ static void
 report_corruption(HeapCheckContext *ctx, char *msg)
 {
 	report_corruption_internal(ctx->tupstore, ctx->tupdesc, ctx->blkno,
-							   ctx->offnum, ctx->attnum, msg);
+							   ctx->offnum, ctx->attphysnum, msg);
 	ctx->is_corrupt = true;
 }
 
@@ -608,7 +608,7 @@ report_toast_corruption(HeapCheckContext *ctx, ToastedAttribute *ta,
 						char *msg)
 {
 	report_corruption_internal(ctx->tupstore, ctx->tupdesc, ta->blkno,
-							   ta->offnum, ta->attnum, msg);
+							   ta->offnum, ta->attphysnum, msg);
 	ctx->is_corrupt = true;
 }
 
@@ -1272,7 +1272,7 @@ check_tuple_attribute(HeapCheckContext *ctx)
 	struct varatt_external toast_pointer;
 
 	infomask = ctx->tuphdr->t_infomask;
-	thisatt = TupleDescAttr(RelationGetDescr(ctx->rel), ctx->attnum);
+	thisatt = TupleDescAttr(RelationGetDescr(ctx->rel), ctx->attphysnum);
 
 	tp = (char *) ctx->tuphdr + ctx->tuphdr->t_hoff;
 
@@ -1287,7 +1287,7 @@ check_tuple_attribute(HeapCheckContext *ctx)
 	}
 
 	/* Skip null values */
-	if (infomask & HEAP_HASNULL && att_isnull(ctx->attnum, ctx->tuphdr->t_bits))
+	if (infomask & HEAP_HASNULL && att_isnull(ctx->attphysnum, ctx->tuphdr->t_bits))
 		return true;
 
 	/* Skip non-varlena values, but update offset first */
@@ -1448,7 +1448,7 @@ check_tuple_attribute(HeapCheckContext *ctx)
 		VARATT_EXTERNAL_GET_POINTER(ta->toast_pointer, attr);
 		ta->blkno = ctx->blkno;
 		ta->offnum = ctx->offnum;
-		ta->attnum = ctx->attnum;
+		ta->attphysnum = ctx->attphysnum;
 		ctx->toasted_attributes = lappend(ctx->toasted_attributes, ta);
 	}
 
@@ -1560,12 +1560,12 @@ check_tuple(HeapCheckContext *ctx)
 	 * attributes collected from the page.
 	 */
 	ctx->offset = 0;
-	for (ctx->attnum = 0; ctx->attnum < ctx->natts; ctx->attnum++)
+	for (ctx->attphysnum = 0; ctx->attphysnum < ctx->natts; ctx->attphysnum++)
 		if (!check_tuple_attribute(ctx))
 			break;				/* cannot continue */
 
-	/* revert attnum to -1 until we again examine individual attributes */
-	ctx->attnum = -1;
+	/* revert attphysnum to -1 until we again examine individual attributes */
+	ctx->attphysnum = -1;
 }
 
 /*
diff --git a/contrib/amcheck/verify_nbtree.c b/contrib/amcheck/verify_nbtree.c
index 2beeebb163..f1d935a538 100644
--- a/contrib/amcheck/verify_nbtree.c
+++ b/contrib/amcheck/verify_nbtree.c
@@ -2575,7 +2575,7 @@ bt_normalize_tuple(BtreeCheckState *state, IndexTuple itup)
 
 		/* Assume untoasted/already normalized datum initially */
 		toast_free[i] = false;
-		normalized[i] = index_getattr(itup, att->attnum,
+		normalized[i] = index_getattr(itup, att->attphysnum,
 									  tupleDescriptor,
 									  &isnull[i]);
 		if (att->attbyval || att->attlen != -1 || isnull[i])
diff --git a/contrib/dblink/dblink.c b/contrib/dblink/dblink.c
index a561d1d652..306d5ec054 100644
--- a/contrib/dblink/dblink.c
+++ b/contrib/dblink/dblink.c
@@ -1694,7 +1694,7 @@ dblink_build_sql_insert(PG_FUNCTION_ARGS)
 	src_pkattvals = get_text_array_contents(src_pkattvals_arry, &src_nitems);
 
 	/*
-	 * There should be one source array key value for each key attnum
+	 * There should be one source array key value for each key attphysnum
 	 */
 	if (src_nitems != pknumatts)
 		ereport(ERROR,
@@ -1708,7 +1708,7 @@ dblink_build_sql_insert(PG_FUNCTION_ARGS)
 	tgt_pkattvals = get_text_array_contents(tgt_pkattvals_arry, &tgt_nitems);
 
 	/*
-	 * There should be one target array key value for each key attnum
+	 * There should be one target array key value for each key attphysnum
 	 */
 	if (tgt_nitems != pknumatts)
 		ereport(ERROR,
@@ -1780,7 +1780,7 @@ dblink_build_sql_delete(PG_FUNCTION_ARGS)
 	tgt_pkattvals = get_text_array_contents(tgt_pkattvals_arry, &tgt_nitems);
 
 	/*
-	 * There should be one target array key value for each key attnum
+	 * There should be one target array key value for each key attphysnum
 	 */
 	if (tgt_nitems != pknumatts)
 		ereport(ERROR,
@@ -1859,7 +1859,7 @@ dblink_build_sql_update(PG_FUNCTION_ARGS)
 	src_pkattvals = get_text_array_contents(src_pkattvals_arry, &src_nitems);
 
 	/*
-	 * There should be one source array key value for each key attnum
+	 * There should be one source array key value for each key attphysnum
 	 */
 	if (src_nitems != pknumatts)
 		ereport(ERROR,
@@ -1873,7 +1873,7 @@ dblink_build_sql_update(PG_FUNCTION_ARGS)
 	tgt_pkattvals = get_text_array_contents(tgt_pkattvals_arry, &tgt_nitems);
 
 	/*
-	 * There should be one target array key value for each key attnum
+	 * There should be one target array key value for each key attphysnum
 	 */
 	if (tgt_nitems != pknumatts)
 		ereport(ERROR,
@@ -2902,7 +2902,7 @@ escape_param_str(const char *str)
  *
  * The user supplies an int2vector of 1-based logical attnums, plus a count
  * argument (the need for the separate count argument is historical, but we
- * still check it).  We check that each attnum corresponds to a valid,
+ * still check it).  We check that each attphysnum corresponds to a valid,
  * non-dropped attribute of the rel.  We do *not* prevent attnums from being
  * listed twice, though the actual use-case for such things is dubious.
  * Note that before Postgres 9.0, the user's attnums were interpreted as
@@ -2923,7 +2923,7 @@ validate_pkattnums(Relation rel,
 	/* Don't take more array elements than there are */
 	pknumatts_arg = Min(pknumatts_arg, pkattnums_arg->dim1);
 
-	/* Must have at least one pk attnum selected */
+	/* Must have at least one pk attphysnum selected */
 	if (pknumatts_arg <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/contrib/file_fdw/file_fdw.c b/contrib/file_fdw/file_fdw.c
index 4773cadec0..7980f67a14 100644
--- a/contrib/file_fdw/file_fdw.c
+++ b/contrib/file_fdw/file_fdw.c
@@ -430,7 +430,7 @@ get_file_fdw_attribute_options(Oid relid)
 	Relation	rel;
 	TupleDesc	tupleDesc;
 	AttrNumber	natts;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	List	   *fnncolumns = NIL;
 	List	   *fncolumns = NIL;
 
@@ -441,9 +441,9 @@ get_file_fdw_attribute_options(Oid relid)
 	natts = tupleDesc->natts;
 
 	/* Retrieve FDW options for all user-defined attributes. */
-	for (attnum = 1; attnum <= natts; attnum++)
+	for (attphysnum = 1; attphysnum <= natts; attphysnum++)
 	{
-		Form_pg_attribute attr = TupleDescAttr(tupleDesc, attnum - 1);
+		Form_pg_attribute attr = TupleDescAttr(tupleDesc, attphysnum - 1);
 		List	   *options;
 		ListCell   *lc;
 
@@ -451,7 +451,7 @@ get_file_fdw_attribute_options(Oid relid)
 		if (attr->attisdropped)
 			continue;
 
-		options = GetForeignColumnOptions(relid, attnum);
+		options = GetForeignColumnOptions(relid, attphysnum);
 		foreach(lc, options)
 		{
 			DefElem    *def = (DefElem *) lfirst(lc);
@@ -852,7 +852,7 @@ check_selective_binary_conversion(RelOptInfo *baserel,
 	ListCell   *lc;
 	Relation	rel;
 	TupleDesc	tupleDesc;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	Bitmapset  *attrs_used = NULL;
 	bool		has_wholerow = false;
 	int			numattrs;
@@ -895,25 +895,25 @@ check_selective_binary_conversion(RelOptInfo *baserel,
 	rel = table_open(foreigntableid, AccessShareLock);
 	tupleDesc = RelationGetDescr(rel);
 
-	while ((attnum = bms_first_member(attrs_used)) >= 0)
+	while ((attphysnum = bms_first_member(attrs_used)) >= 0)
 	{
 		/* Adjust for system attributes. */
-		attnum += FirstLowInvalidHeapAttributeNumber;
+		attphysnum += FirstLowInvalidHeapAttributeNumber;
 
-		if (attnum == 0)
+		if (attphysnum == 0)
 		{
 			has_wholerow = true;
 			break;
 		}
 
 		/* Ignore system attributes. */
-		if (attnum < 0)
+		if (attphysnum < 0)
 			continue;
 
 		/* Get user attributes. */
-		if (attnum > 0)
+		if (attphysnum > 0)
 		{
-			Form_pg_attribute attr = TupleDescAttr(tupleDesc, attnum - 1);
+			Form_pg_attribute attr = TupleDescAttr(tupleDesc, attphysnum - 1);
 			char	   *attname = NameStr(attr->attname);
 
 			/* Skip dropped attributes (probably shouldn't see any here). */
diff --git a/contrib/lo/lo.c b/contrib/lo/lo.c
index 457be26c4e..367e2fb866 100644
--- a/contrib/lo/lo.c
+++ b/contrib/lo/lo.c
@@ -24,7 +24,7 @@ Datum
 lo_manage(PG_FUNCTION_ARGS)
 {
 	TriggerData *trigdata = (TriggerData *) fcinfo->context;
-	int			attnum;			/* attribute number to monitor	*/
+	int			attphysnum;			/* attribute number to monitor	*/
 	char	  **args;			/* Args containing attr name	*/
 	TupleDesc	tupdesc;		/* Tuple Descriptor				*/
 	HeapTuple	rettuple;		/* Tuple to be returned			*/
@@ -61,9 +61,9 @@ lo_manage(PG_FUNCTION_ARGS)
 	isdelete = TRIGGER_FIRED_BY_DELETE(trigdata->tg_event);
 
 	/* Get the column we're interested in */
-	attnum = SPI_fnumber(tupdesc, args[0]);
+	attphysnum = SPI_fnumber(tupdesc, args[0]);
 
-	if (attnum <= 0)
+	if (attphysnum <= 0)
 		elog(ERROR, "%s: column \"%s\" does not exist",
 			 trigdata->tg_trigger->tgname, args[0]);
 
@@ -74,10 +74,10 @@ lo_manage(PG_FUNCTION_ARGS)
 	 * object associated with the original value is unlinked.
 	 */
 	if (newtuple != NULL &&
-		bms_is_member(attnum - FirstLowInvalidHeapAttributeNumber, trigdata->tg_updatedcols))
+		bms_is_member(attphysnum - FirstLowInvalidHeapAttributeNumber, trigdata->tg_updatedcols))
 	{
-		char	   *orig = SPI_getvalue(trigtuple, tupdesc, attnum);
-		char	   *newv = SPI_getvalue(newtuple, tupdesc, attnum);
+		char	   *orig = SPI_getvalue(trigtuple, tupdesc, attphysnum);
+		char	   *newv = SPI_getvalue(newtuple, tupdesc, attphysnum);
 
 		if (orig != NULL && (newv == NULL || strcmp(orig, newv) != 0))
 			DirectFunctionCall1(be_lo_unlink,
@@ -96,7 +96,7 @@ lo_manage(PG_FUNCTION_ARGS)
 	 */
 	if (isdelete)
 	{
-		char	   *orig = SPI_getvalue(trigtuple, tupdesc, attnum);
+		char	   *orig = SPI_getvalue(trigtuple, tupdesc, attphysnum);
 
 		if (orig != NULL)
 		{
diff --git a/contrib/pageinspect/expected/brin.out b/contrib/pageinspect/expected/brin.out
index d19cdc3b95..832117b565 100644
--- a/contrib/pageinspect/expected/brin.out
+++ b/contrib/pageinspect/expected/brin.out
@@ -42,10 +42,10 @@ SELECT * FROM brin_revmap_data(get_raw_page('test1_a_idx', 1)) LIMIT 5;
 (5 rows)
 
 SELECT * FROM brin_page_items(get_raw_page('test1_a_idx', 2), 'test1_a_idx')
-    ORDER BY blknum, attnum LIMIT 5;
- itemoffset | blknum | attnum | allnulls | hasnulls | placeholder |  value   
-------------+--------+--------+----------+----------+-------------+----------
-          1 |      0 |      1 | f        | f        | f           | {1 .. 1}
+    ORDER BY blknum, attphysnum LIMIT 5;
+ itemoffset | blknum | attphysnum | allnulls | hasnulls | placeholder |  value   
+------------+--------+------------+----------+----------+-------------+----------
+          1 |      0 |          1 | f        | f        | f           | {1 .. 1}
 (1 row)
 
 -- Failure for non-BRIN index.
diff --git a/contrib/pageinspect/pageinspect--1.2--1.3.sql b/contrib/pageinspect/pageinspect--1.2--1.3.sql
index 9c55a6e598..9d3af061b6 100644
--- a/contrib/pageinspect/pageinspect--1.2--1.3.sql
+++ b/contrib/pageinspect/pageinspect--1.2--1.3.sql
@@ -34,7 +34,7 @@ LANGUAGE C STRICT;
 CREATE FUNCTION brin_page_items(IN page bytea, IN index_oid regclass,
 	OUT itemoffset int,
 	OUT blknum int,
-	OUT attnum int,
+	OUT attphysnum int,
 	OUT allnulls bool,
 	OUT hasnulls bool,
 	OUT placeholder bool,
diff --git a/contrib/pageinspect/pageinspect--1.5.sql b/contrib/pageinspect/pageinspect--1.5.sql
index 1e40c3c97e..1e759b504d 100644
--- a/contrib/pageinspect/pageinspect--1.5.sql
+++ b/contrib/pageinspect/pageinspect--1.5.sql
@@ -219,7 +219,7 @@ LANGUAGE C STRICT PARALLEL SAFE;
 CREATE FUNCTION brin_page_items(IN page bytea, IN index_oid regclass,
 	OUT itemoffset int,
 	OUT blknum int,
-	OUT attnum int,
+	OUT attphysnum int,
 	OUT allnulls bool,
 	OUT hasnulls bool,
 	OUT placeholder bool,
diff --git a/contrib/pageinspect/pageinspect--1.8--1.9.sql b/contrib/pageinspect/pageinspect--1.8--1.9.sql
index be89a64ca1..389d981f82 100644
--- a/contrib/pageinspect/pageinspect--1.8--1.9.sql
+++ b/contrib/pageinspect/pageinspect--1.8--1.9.sql
@@ -127,7 +127,7 @@ DROP FUNCTION brin_page_items(IN page bytea, IN index_oid regclass);
 CREATE FUNCTION brin_page_items(IN page bytea, IN index_oid regclass,
     OUT itemoffset int,
     OUT blknum int8,
-    OUT attnum int,
+    OUT attphysnum int,
     OUT allnulls bool,
     OUT hasnulls bool,
     OUT placeholder bool,
diff --git a/contrib/pageinspect/sql/brin.sql b/contrib/pageinspect/sql/brin.sql
index 45098c1ef5..555e83f98a 100644
--- a/contrib/pageinspect/sql/brin.sql
+++ b/contrib/pageinspect/sql/brin.sql
@@ -13,7 +13,7 @@ SELECT * FROM brin_revmap_data(get_raw_page('test1_a_idx', 0)) LIMIT 5;
 SELECT * FROM brin_revmap_data(get_raw_page('test1_a_idx', 1)) LIMIT 5;
 
 SELECT * FROM brin_page_items(get_raw_page('test1_a_idx', 2), 'test1_a_idx')
-    ORDER BY blknum, attnum LIMIT 5;
+    ORDER BY blknum, attphysnum LIMIT 5;
 
 -- Failure for non-BRIN index.
 CREATE INDEX test1_a_btree ON test1 (a);
diff --git a/contrib/postgres_fdw/deparse.c b/contrib/postgres_fdw/deparse.c
index 8f4d8a5022..5cd519511e 100644
--- a/contrib/postgres_fdw/deparse.c
+++ b/contrib/postgres_fdw/deparse.c
@@ -1890,13 +1890,13 @@ deparseInsertSql(StringInfo buf, RangeTblEntry *rte,
 		first = true;
 		foreach(lc, targetAttrs)
 		{
-			int			attnum = lfirst_int(lc);
+			int			attphysnum = lfirst_int(lc);
 
 			if (!first)
 				appendStringInfoString(buf, ", ");
 			first = false;
 
-			deparseColumnRef(buf, rtindex, attnum, rte, false);
+			deparseColumnRef(buf, rtindex, attphysnum, rte, false);
 		}
 
 		appendStringInfoString(buf, ") VALUES (");
@@ -1905,8 +1905,8 @@ deparseInsertSql(StringInfo buf, RangeTblEntry *rte,
 		first = true;
 		foreach(lc, targetAttrs)
 		{
-			int			attnum = lfirst_int(lc);
-			Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
+			int			attphysnum = lfirst_int(lc);
+			Form_pg_attribute attr = TupleDescAttr(tupdesc, attphysnum - 1);
 
 			if (!first)
 				appendStringInfoString(buf, ", ");
@@ -1971,8 +1971,8 @@ rebuildInsertSql(StringInfo buf, Relation rel,
 		first = true;
 		foreach(lc, target_attrs)
 		{
-			int			attnum = lfirst_int(lc);
-			Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
+			int			attphysnum = lfirst_int(lc);
+			Form_pg_attribute attr = TupleDescAttr(tupdesc, attphysnum - 1);
 
 			if (!first)
 				appendStringInfoString(buf, ", ");
@@ -2021,14 +2021,14 @@ deparseUpdateSql(StringInfo buf, RangeTblEntry *rte,
 	first = true;
 	foreach(lc, targetAttrs)
 	{
-		int			attnum = lfirst_int(lc);
-		Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
+		int			attphysnum = lfirst_int(lc);
+		Form_pg_attribute attr = TupleDescAttr(tupdesc, attphysnum - 1);
 
 		if (!first)
 			appendStringInfoString(buf, ", ");
 		first = false;
 
-		deparseColumnRef(buf, rtindex, attnum, rte, false);
+		deparseColumnRef(buf, rtindex, attphysnum, rte, false);
 		if (attr->attgenerated)
 			appendStringInfoString(buf, " = DEFAULT");
 		else
@@ -2099,7 +2099,7 @@ deparseDirectUpdateSql(StringInfo buf, PlannerInfo *root,
 	forboth(lc, targetlist, lc2, targetAttrs)
 	{
 		TargetEntry *tle = lfirst_node(TargetEntry, lc);
-		int			attnum = lfirst_int(lc2);
+		int			attphysnum = lfirst_int(lc2);
 
 		/* update's new-value expressions shouldn't be resjunk */
 		Assert(!tle->resjunk);
@@ -2108,7 +2108,7 @@ deparseDirectUpdateSql(StringInfo buf, PlannerInfo *root,
 			appendStringInfoString(buf, ", ");
 		first = false;
 
-		deparseColumnRef(buf, rtindex, attnum, rte, false);
+		deparseColumnRef(buf, rtindex, attphysnum, rte, false);
 		appendStringInfoString(buf, " = ");
 		deparseExpr((Expr *) tle->expr, &context);
 	}
diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c
index d56951153b..10effe7387 100644
--- a/contrib/postgres_fdw/postgres_fdw.c
+++ b/contrib/postgres_fdw/postgres_fdw.c
@@ -197,7 +197,7 @@ typedef struct PgFdwModifyState
 	List	   *retrieved_attrs;	/* attr numbers retrieved by RETURNING */
 
 	/* info about parameters for prepared statement */
-	AttrNumber	ctidAttno;		/* attnum of input resjunk ctid column */
+	AttrNumber	ctidAttno;		/* attphysnum of input resjunk ctid column */
 	int			p_nums;			/* number of parameters to transmit */
 	FmgrInfo   *p_flinfo;		/* output conversion functions for them */
 
@@ -240,8 +240,8 @@ typedef struct PgFdwDirectModifyState
 	int			next_tuple;		/* index of next one to return */
 	Relation	resultRel;		/* relcache entry for the target relation */
 	AttrNumber *attnoMap;		/* array of attnums of input user columns */
-	AttrNumber	ctidAttno;		/* attnum of input ctid column */
-	AttrNumber	oidAttno;		/* attnum of input oid column */
+	AttrNumber	ctidAttno;		/* attphysnum of input ctid column */
+	AttrNumber	oidAttno;		/* attphysnum of input oid column */
 	bool		hasSystemCols;	/* are there system columns of resultRel? */
 
 	/* working memory context */
@@ -1800,14 +1800,14 @@ postgresPlanForeignModify(PlannerInfo *root,
 		 rel->trigdesc->trig_update_before_row))
 	{
 		TupleDesc	tupdesc = RelationGetDescr(rel);
-		int			attnum;
+		int			attphysnum;
 
-		for (attnum = 1; attnum <= tupdesc->natts; attnum++)
+		for (attphysnum = 1; attphysnum <= tupdesc->natts; attphysnum++)
 		{
-			Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
+			Form_pg_attribute attr = TupleDescAttr(tupdesc, attphysnum - 1);
 
 			if (!attr->attisdropped)
-				targetAttrs = lappend_int(targetAttrs, attnum);
+				targetAttrs = lappend_int(targetAttrs, attphysnum);
 		}
 	}
 	else if (operation == CMD_UPDATE)
@@ -2139,7 +2139,7 @@ postgresBeginForeignInsert(ModifyTableState *mtstate,
 	Relation	rel = resultRelInfo->ri_RelationDesc;
 	RangeTblEntry *rte;
 	TupleDesc	tupdesc = RelationGetDescr(rel);
-	int			attnum;
+	int			attphysnum;
 	int			values_end_len;
 	StringInfoData sql;
 	List	   *targetAttrs = NIL;
@@ -2164,12 +2164,12 @@ postgresBeginForeignInsert(ModifyTableState *mtstate,
 	initStringInfo(&sql);
 
 	/* We transmit all columns that are defined in the foreign table. */
-	for (attnum = 1; attnum <= tupdesc->natts; attnum++)
+	for (attphysnum = 1; attphysnum <= tupdesc->natts; attphysnum++)
 	{
-		Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
+		Form_pg_attribute attr = TupleDescAttr(tupdesc, attphysnum - 1);
 
 		if (!attr->attisdropped)
-			targetAttrs = lappend_int(targetAttrs, attnum);
+			targetAttrs = lappend_int(targetAttrs, attphysnum);
 	}
 
 	/* Check if we add the ON CONFLICT clause to the remote query. */
@@ -4026,8 +4026,8 @@ create_foreign_modify(EState *estate,
 		/* Set up for remaining transmittable parameters */
 		foreach(lc, fmstate->target_attrs)
 		{
-			int			attnum = lfirst_int(lc);
-			Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
+			int			attphysnum = lfirst_int(lc);
+			Form_pg_attribute attr = TupleDescAttr(tupdesc, attphysnum - 1);
 
 			Assert(!attr->attisdropped);
 
@@ -4279,15 +4279,15 @@ convert_prep_stmt_params(PgFdwModifyState *fmstate,
 			j = (tupleid != NULL) ? 1 : 0;
 			foreach(lc, fmstate->target_attrs)
 			{
-				int			attnum = lfirst_int(lc);
-				Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
+				int			attphysnum = lfirst_int(lc);
+				Form_pg_attribute attr = TupleDescAttr(tupdesc, attphysnum - 1);
 				Datum		value;
 				bool		isnull;
 
 				/* Ignore generated columns; they are set to DEFAULT */
 				if (attr->attgenerated)
 					continue;
-				value = slot_getattr(slots[i], attnum, &isnull);
+				value = slot_getattr(slots[i], attphysnum, &isnull);
 				if (isnull)
 					p_values[pindex] = NULL;
 				else
@@ -5330,10 +5330,10 @@ postgresImportForeignSchema(ImportForeignSchemaStmt *stmt, Oid serverOid)
 							   "  JOIN pg_namespace n ON "
 							   "    relnamespace = n.oid "
 							   "  LEFT JOIN pg_attribute a ON "
-							   "    attrelid = c.oid AND attnum > 0 "
+							   "    attrelid = c.oid AND attphysnum > 0 "
 							   "      AND NOT attisdropped "
 							   "  LEFT JOIN pg_attrdef ad ON "
-							   "    adrelid = c.oid AND adnum = attnum ");
+							   "    adrelid = c.oid AND adnum = attphysnum ");
 
 		if (import_collate)
 			appendStringInfoString(&buf,
@@ -5383,7 +5383,7 @@ postgresImportForeignSchema(ImportForeignSchemaStmt *stmt, Oid serverOid)
 		}
 
 		/* Append ORDER BY at the end of query to ensure output ordering */
-		appendStringInfoString(&buf, " ORDER BY c.relname, a.attnum");
+		appendStringInfoString(&buf, " ORDER BY c.relname, a.attphysnum");
 
 		/* Fetch the data */
 		res = pgfdw_exec_query(conn, buf.data, NULL);
diff --git a/contrib/sepgsql/dml.c b/contrib/sepgsql/dml.c
index 3bb98dfb06..4f43665f70 100644
--- a/contrib/sepgsql/dml.c
+++ b/contrib/sepgsql/dml.c
@@ -61,7 +61,7 @@ fixup_whole_row_references(Oid relOid, Bitmapset *columns)
 
 	for (attno = 1; attno <= natts; attno++)
 	{
-		tuple = SearchSysCache2(ATTNUM,
+		tuple = SearchSysCache2(ATTPHYSNUM,
 								ObjectIdGetDatum(relOid),
 								Int16GetDatum(attno));
 		if (!HeapTupleIsValid(tuple))
@@ -117,7 +117,7 @@ fixup_inherited_columns(Oid parentId, Oid childId, Bitmapset *columns)
 		}
 
 		attname = get_attname(parentId, attno, false);
-		attno = get_attnum(childId, attname);
+		attno = get_attphysnum(childId, attname);
 		if (attno == InvalidAttrNumber)
 			elog(ERROR, "cache lookup failed for attribute %s of relation %u",
 				 attname, childId);
@@ -232,7 +232,7 @@ check_relation_privileges(Oid relOid,
 
 	while ((index = bms_first_member(columns)) >= 0)
 	{
-		AttrNumber	attnum;
+		AttrNumber	attphysnum;
 		uint32		column_perms = 0;
 
 		if (bms_is_member(index, selected))
@@ -251,11 +251,11 @@ check_relation_privileges(Oid relOid,
 			continue;
 
 		/* obtain column's permission */
-		attnum = index + FirstLowInvalidHeapAttributeNumber;
+		attphysnum = index + FirstLowInvalidHeapAttributeNumber;
 
 		object.classId = RelationRelationId;
 		object.objectId = relOid;
-		object.objectSubId = attnum;
+		object.objectSubId = attphysnum;
 		audit_name = getObjectDescription(&object, false);
 
 		result = sepgsql_avc_check_perms(&object,
diff --git a/contrib/sepgsql/label.c b/contrib/sepgsql/label.c
index e4c98b7eae..97dccf385f 100644
--- a/contrib/sepgsql/label.c
+++ b/contrib/sepgsql/label.c
@@ -805,7 +805,7 @@ exec_object_restorecon(struct selabel_handle *sehnd, Oid catalogId)
 
 				object.classId = RelationRelationId;
 				object.objectId = attForm->attrelid;
-				object.objectSubId = attForm->attnum;
+				object.objectSubId = attForm->attphysnum;
 				break;
 
 			case ProcedureRelationId:
diff --git a/contrib/sepgsql/relation.c b/contrib/sepgsql/relation.c
index 8767988c4d..b1ad4a6636 100644
--- a/contrib/sepgsql/relation.c
+++ b/contrib/sepgsql/relation.c
@@ -40,7 +40,7 @@ static void sepgsql_index_modify(Oid indexOid);
  * although it also defines columns in addition to table.
  */
 void
-sepgsql_attribute_post_create(Oid relOid, AttrNumber attnum)
+sepgsql_attribute_post_create(Oid relOid, AttrNumber attphysnum)
 {
 	Relation	rel;
 	ScanKeyData skey[2];
@@ -72,17 +72,17 @@ sepgsql_attribute_post_create(Oid relOid, AttrNumber attnum)
 				BTEqualStrategyNumber, F_OIDEQ,
 				ObjectIdGetDatum(relOid));
 	ScanKeyInit(&skey[1],
-				Anum_pg_attribute_attnum,
+				Anum_pg_attribute_attphysnum,
 				BTEqualStrategyNumber, F_INT2EQ,
-				Int16GetDatum(attnum));
+				Int16GetDatum(attphysnum));
 
-	sscan = systable_beginscan(rel, AttributeRelidNumIndexId, true,
+	sscan = systable_beginscan(rel, AttributeRelidPhysNumIndexId, true,
 							   SnapshotSelf, 2, &skey[0]);
 
 	tuple = systable_getnext(sscan);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "could not find tuple for column %d of relation %u",
-			 attnum, relOid);
+			 attphysnum, relOid);
 
 	attForm = (Form_pg_attribute) GETSTRUCT(tuple);
 
@@ -114,7 +114,7 @@ sepgsql_attribute_post_create(Oid relOid, AttrNumber attnum)
 	 */
 	object.classId = RelationRelationId;
 	object.objectId = relOid;
-	object.objectSubId = attnum;
+	object.objectSubId = attphysnum;
 	SetSecurityLabel(&object, SEPGSQL_LABEL_TAG, ncontext);
 
 	systable_endscan(sscan);
@@ -130,7 +130,7 @@ sepgsql_attribute_post_create(Oid relOid, AttrNumber attnum)
  * It checks privileges to drop the supplied column.
  */
 void
-sepgsql_attribute_drop(Oid relOid, AttrNumber attnum)
+sepgsql_attribute_drop(Oid relOid, AttrNumber attphysnum)
 {
 	ObjectAddress object;
 	char	   *audit_name;
@@ -144,7 +144,7 @@ sepgsql_attribute_drop(Oid relOid, AttrNumber attnum)
 	 */
 	object.classId = RelationRelationId;
 	object.objectId = relOid;
-	object.objectSubId = attnum;
+	object.objectSubId = attphysnum;
 	audit_name = getObjectIdentity(&object, false);
 
 	sepgsql_avc_check_perms(&object,
@@ -162,7 +162,7 @@ sepgsql_attribute_drop(Oid relOid, AttrNumber attnum)
  * by the `seclabel'.
  */
 void
-sepgsql_attribute_relabel(Oid relOid, AttrNumber attnum,
+sepgsql_attribute_relabel(Oid relOid, AttrNumber attphysnum,
 						  const char *seclabel)
 {
 	ObjectAddress object;
@@ -176,7 +176,7 @@ sepgsql_attribute_relabel(Oid relOid, AttrNumber attnum,
 
 	object.classId = RelationRelationId;
 	object.objectId = relOid;
-	object.objectSubId = attnum;
+	object.objectSubId = attphysnum;
 	audit_name = getObjectIdentity(&object, false);
 
 	/*
@@ -206,7 +206,7 @@ sepgsql_attribute_relabel(Oid relOid, AttrNumber attnum,
  * It checks privileges to alter the supplied column.
  */
 void
-sepgsql_attribute_setattr(Oid relOid, AttrNumber attnum)
+sepgsql_attribute_setattr(Oid relOid, AttrNumber attphysnum)
 {
 	ObjectAddress object;
 	char	   *audit_name;
@@ -220,7 +220,7 @@ sepgsql_attribute_setattr(Oid relOid, AttrNumber attnum)
 	 */
 	object.classId = RelationRelationId;
 	object.objectId = relOid;
-	object.objectSubId = attnum;
+	object.objectSubId = attphysnum;
 	audit_name = getObjectIdentity(&object, false);
 
 	sepgsql_avc_check_perms(&object,
@@ -363,7 +363,7 @@ sepgsql_relation_post_create(Oid relOid)
 					BTEqualStrategyNumber, F_OIDEQ,
 					ObjectIdGetDatum(relOid));
 
-		ascan = systable_beginscan(arel, AttributeRelidNumIndexId, true,
+		ascan = systable_beginscan(arel, AttributeRelidPhysNumIndexId, true,
 								   SnapshotSelf, 1, &akey);
 
 		while (HeapTupleIsValid(atup = systable_getnext(ascan)))
@@ -392,7 +392,7 @@ sepgsql_relation_post_create(Oid relOid)
 
 			object.classId = RelationRelationId;
 			object.objectId = relOid;
-			object.objectSubId = attForm->attnum;
+			object.objectSubId = attForm->attphysnum;
 			SetSecurityLabel(&object, SEPGSQL_LABEL_TAG, ccontext);
 
 			pfree(ccontext);
@@ -490,7 +490,7 @@ sepgsql_relation_drop(Oid relOid)
 		HeapTuple	atttup;
 		int			i;
 
-		attrList = SearchSysCacheList1(ATTNUM, ObjectIdGetDatum(relOid));
+		attrList = SearchSysCacheList1(ATTPHYSNUM, ObjectIdGetDatum(relOid));
 		for (i = 0; i < attrList->n_members; i++)
 		{
 			atttup = &attrList->members[i]->tuple;
@@ -501,7 +501,7 @@ sepgsql_relation_drop(Oid relOid)
 
 			object.classId = RelationRelationId;
 			object.objectId = relOid;
-			object.objectSubId = attForm->attnum;
+			object.objectSubId = attForm->attphysnum;
 			audit_name = getObjectIdentity(&object, false);
 
 			sepgsql_avc_check_perms(&object,
diff --git a/contrib/sepgsql/sepgsql.h b/contrib/sepgsql/sepgsql.h
index 70f6203496..86e1562630 100644
--- a/contrib/sepgsql/sepgsql.h
+++ b/contrib/sepgsql/sepgsql.h
@@ -307,11 +307,11 @@ extern void sepgsql_schema_rename(Oid namespaceId);
 /*
  * relation.c
  */
-extern void sepgsql_attribute_post_create(Oid relOid, AttrNumber attnum);
-extern void sepgsql_attribute_drop(Oid relOid, AttrNumber attnum);
-extern void sepgsql_attribute_relabel(Oid relOid, AttrNumber attnum,
+extern void sepgsql_attribute_post_create(Oid relOid, AttrNumber attphysnum);
+extern void sepgsql_attribute_drop(Oid relOid, AttrNumber attphysnum);
+extern void sepgsql_attribute_relabel(Oid relOid, AttrNumber attphysnum,
 									  const char *seclabel);
-extern void sepgsql_attribute_setattr(Oid relOid, AttrNumber attnum);
+extern void sepgsql_attribute_setattr(Oid relOid, AttrNumber attphysnum);
 extern void sepgsql_relation_post_create(Oid relOid);
 extern void sepgsql_relation_drop(Oid relOid);
 extern void sepgsql_relation_truncate(Oid relOid);
diff --git a/contrib/spi/autoinc.c b/contrib/spi/autoinc.c
index 8bf742230e..1b82c2ae29 100644
--- a/contrib/spi/autoinc.c
+++ b/contrib/spi/autoinc.c
@@ -70,23 +70,23 @@ autoinc(PG_FUNCTION_ARGS)
 
 	for (i = 0; i < nargs;)
 	{
-		int			attnum = SPI_fnumber(tupdesc, args[i]);
+		int			attphysnum = SPI_fnumber(tupdesc, args[i]);
 		int32		val;
 		Datum		seqname;
 
-		if (attnum <= 0)
+		if (attphysnum <= 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
 					 errmsg("\"%s\" has no attribute \"%s\"",
 							relname, args[i])));
 
-		if (SPI_gettypeid(tupdesc, attnum) != INT4OID)
+		if (SPI_gettypeid(tupdesc, attphysnum) != INT4OID)
 			ereport(ERROR,
 					(errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
 					 errmsg("attribute \"%s\" of \"%s\" must be type INT4",
 							args[i], relname)));
 
-		val = DatumGetInt32(SPI_getbinval(rettuple, tupdesc, attnum, &isnull));
+		val = DatumGetInt32(SPI_getbinval(rettuple, tupdesc, attphysnum, &isnull));
 
 		if (!isnull && val != 0)
 		{
@@ -95,7 +95,7 @@ autoinc(PG_FUNCTION_ARGS)
 		}
 
 		i++;
-		chattrs[chnattrs] = attnum;
+		chattrs[chnattrs] = attphysnum;
 		seqname = CStringGetTextDatum(args[i]);
 		newvals[chnattrs] = DirectFunctionCall1(nextval, seqname);
 		/* nextval now returns int64; coerce down to int32 */
diff --git a/contrib/spi/insert_username.c b/contrib/spi/insert_username.c
index a2e1747ff7..fbf3514942 100644
--- a/contrib/spi/insert_username.c
+++ b/contrib/spi/insert_username.c
@@ -31,7 +31,7 @@ insert_username(PG_FUNCTION_ARGS)
 	Relation	rel;			/* triggered relation */
 	HeapTuple	rettuple = NULL;
 	TupleDesc	tupdesc;		/* tuple description */
-	int			attnum;
+	int			attphysnum;
 
 	/* sanity checks from autoinc.c */
 	if (!CALLED_AS_TRIGGER(fcinfo))
@@ -65,14 +65,14 @@ insert_username(PG_FUNCTION_ARGS)
 	args = trigger->tgargs;
 	tupdesc = rel->rd_att;
 
-	attnum = SPI_fnumber(tupdesc, args[0]);
+	attphysnum = SPI_fnumber(tupdesc, args[0]);
 
-	if (attnum <= 0)
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
 				 errmsg("\"%s\" has no attribute \"%s\"", relname, args[0])));
 
-	if (SPI_gettypeid(tupdesc, attnum) != TEXTOID)
+	if (SPI_gettypeid(tupdesc, attphysnum) != TEXTOID)
 		ereport(ERROR,
 				(errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
 				 errmsg("attribute \"%s\" of \"%s\" must be type TEXT",
@@ -84,7 +84,7 @@ insert_username(PG_FUNCTION_ARGS)
 
 	/* construct new tuple */
 	rettuple = heap_modify_tuple_by_cols(rettuple, tupdesc,
-										 1, &attnum, &newval, &newnull);
+										 1, &attphysnum, &newval, &newnull);
 
 	pfree(relname);
 
diff --git a/contrib/spi/moddatetime.c b/contrib/spi/moddatetime.c
index 3eb7004de9..6291ca4816 100644
--- a/contrib/spi/moddatetime.c
+++ b/contrib/spi/moddatetime.c
@@ -32,7 +32,7 @@ moddatetime(PG_FUNCTION_ARGS)
 	TriggerData *trigdata = (TriggerData *) fcinfo->context;
 	Trigger    *trigger;		/* to get trigger name */
 	int			nargs;			/* # of arguments */
-	int			attnum;			/* positional number of field to change */
+	int			attphysnum;			/* positional number of field to change */
 	Oid			atttypid;		/* type OID of field to change */
 	Datum		newdt;			/* The current datetime. */
 	bool		newdtnull;		/* null flag for it */
@@ -82,13 +82,13 @@ moddatetime(PG_FUNCTION_ARGS)
 	 * This gets the position in the tuple of the field we want. args[0] being
 	 * the name of the field to update, as passed in from the trigger.
 	 */
-	attnum = SPI_fnumber(tupdesc, args[0]);
+	attphysnum = SPI_fnumber(tupdesc, args[0]);
 
 	/*
 	 * This is where we check to see if the field we are supposed to update
 	 * even exists.
 	 */
-	if (attnum <= 0)
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
 				 errmsg("\"%s\" has no attribute \"%s\"",
@@ -98,7 +98,7 @@ moddatetime(PG_FUNCTION_ARGS)
 	 * Check the target field has an allowed type, and get the current
 	 * datetime as a value of that type.
 	 */
-	atttypid = SPI_gettypeid(tupdesc, attnum);
+	atttypid = SPI_gettypeid(tupdesc, attphysnum);
 	if (atttypid == TIMESTAMPOID)
 		newdt = DirectFunctionCall3(timestamp_in,
 									CStringGetDatum("now"),
@@ -121,7 +121,7 @@ moddatetime(PG_FUNCTION_ARGS)
 
 	/* Replace the attnum'th column with newdt */
 	rettuple = heap_modify_tuple_by_cols(rettuple, tupdesc,
-										 1, &attnum, &newdt, &newdtnull);
+										 1, &attphysnum, &newdt, &newdtnull);
 
 	/* Clean up */
 	pfree(relname);
diff --git a/contrib/test_decoding/test_decoding.c b/contrib/test_decoding/test_decoding.c
index 3736da6784..3954427214 100644
--- a/contrib/test_decoding/test_decoding.c
+++ b/contrib/test_decoding/test_decoding.c
@@ -554,7 +554,7 @@ tuple_to_stringinfo(StringInfo s, TupleDesc tupdesc, HeapTuple tuple, bool skip_
 		 * Don't print system columns, oid will already have been printed if
 		 * present.
 		 */
-		if (attr->attnum < 0)
+		if (attr->attphysnum < 0)
 			continue;
 
 		typid = attr->atttypid;
diff --git a/contrib/vacuumlo/vacuumlo.c b/contrib/vacuumlo/vacuumlo.c
index b7c8f2c805..6a86c8cec8 100644
--- a/contrib/vacuumlo/vacuumlo.c
+++ b/contrib/vacuumlo/vacuumlo.c
@@ -193,7 +193,7 @@ vacuumlo(const char *database, const struct _param *param)
 	buf[0] = '\0';
 	strcat(buf, "SELECT s.nspname, c.relname, a.attname ");
 	strcat(buf, "FROM pg_class c, pg_attribute a, pg_namespace s, pg_type t ");
-	strcat(buf, "WHERE a.attnum > 0 AND NOT a.attisdropped ");
+	strcat(buf, "WHERE a.attphysnum > 0 AND NOT a.attisdropped ");
 	strcat(buf, "      AND a.attrelid = c.oid ");
 	strcat(buf, "      AND a.atttypid = t.oid ");
 	strcat(buf, "      AND c.relnamespace = s.oid ");
diff --git a/doc/src/sgml/amcheck.sgml b/doc/src/sgml/amcheck.sgml
index 5d61a33936..bd6e7ef77f 100644
--- a/doc/src/sgml/amcheck.sgml
+++ b/doc/src/sgml/amcheck.sgml
@@ -91,7 +91,7 @@ ORDER BY c.relpages DESC LIMIT 10;
                 | pg_description_o_c_o_index      |       21
                 | pg_attribute_relid_attnam_index |       14
                 | pg_proc_oid_index               |       10
-                | pg_attribute_relid_attnum_index |        9
+                | pg_attribute_relid_attphysnum_index |        9
                 | pg_amproc_fam_proc_index        |        5
                 | pg_amop_opr_fam_index           |        5
                 | pg_amop_fam_strat_index         |        5
@@ -213,7 +213,7 @@ SET client_min_messages = DEBUG1;
                     endblock bigint,
                     blkno OUT bigint,
                     offnum OUT integer,
-                    attnum OUT integer,
+                    attphysnum OUT integer,
                     msg OUT text)
       returns setof record
      </function>
diff --git a/doc/src/sgml/fdwhandler.sgml b/doc/src/sgml/fdwhandler.sgml
index d0b5951019..e0f95fcfd4 100644
--- a/doc/src/sgml/fdwhandler.sgml
+++ b/doc/src/sgml/fdwhandler.sgml
@@ -1759,7 +1759,7 @@ GetForeignTable(Oid relid);
     <para>
 <programlisting>
 List *
-GetForeignColumnOptions(Oid relid, AttrNumber attnum);
+GetForeignColumnOptions(Oid relid, AttrNumber attphysnum);
 </programlisting>
 
      This function returns the per-column FDW options for the column with the
diff --git a/doc/src/sgml/pageinspect.sgml b/doc/src/sgml/pageinspect.sgml
index d4ee34ee0f..4bfcf3c56d 100644
--- a/doc/src/sgml/pageinspect.sgml
+++ b/doc/src/sgml/pageinspect.sgml
@@ -564,8 +564,8 @@ test=# SELECT * FROM brin_revmap_data(get_raw_page('brinidx', 2)) LIMIT 5;
 <screen>
 test=# SELECT * FROM brin_page_items(get_raw_page('brinidx', 5),
                                      'brinidx')
-       ORDER BY blknum, attnum LIMIT 6;
- itemoffset | blknum | attnum | allnulls | hasnulls | placeholder |    value
+       ORDER BY blknum, attphysnum LIMIT 6;
+ itemoffset | blknum | attphysnum | allnulls | hasnulls | placeholder |    value
 ------------+--------+--------+----------+----------+-------------+--------------
         137 |      0 |      1 | t        | f        | f           |
         137 |      0 |      2 | f        | f        | f           | {1 .. 88}
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 65bb0a6a3f..b029355b50 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -2289,7 +2289,7 @@ Tue Oct 26 21:40:57 CEST 1999
 <programlisting>
 =&gt; <userinput>SELECT format('create index on my_table(%I)', attname)</userinput>
 -&gt; <userinput>FROM pg_attribute</userinput>
--&gt; <userinput>WHERE attrelid = 'my_table'::regclass AND attnum &gt; 0</userinput>
+-&gt; <userinput>WHERE attrelid = 'my_table'::regclass AND attphysnum &gt; 0</userinput>
 -&gt; <userinput>ORDER BY attnum</userinput>
 -&gt; <userinput>\gexec</userinput>
 CREATE INDEX
diff --git a/doc/src/sgml/sources.sgml b/doc/src/sgml/sources.sgml
index 5186d75d61..b6dab7ff47 100644
--- a/doc/src/sgml/sources.sgml
+++ b/doc/src/sgml/sources.sgml
@@ -326,7 +326,7 @@ ereport(ERROR,
    </listitem>
    <listitem>
     <para>
-     <function>errtablecol(Relation rel, int attnum)</function> specifies
+     <function>errtablecol(Relation rel, int attphysnum)</function> specifies
      a column whose name, table name, and schema name should be included as
      auxiliary fields in the error report.
     </para>
diff --git a/doc/src/sgml/trigger.sgml b/doc/src/sgml/trigger.sgml
index 04e702a795..6234edbc12 100644
--- a/doc/src/sgml/trigger.sgml
+++ b/doc/src/sgml/trigger.sgml
@@ -803,7 +803,7 @@ typedef struct Trigger
        <para>
         As an example, to determine whether a column with attribute number
         <varname>attnum</varname> (1-based) is a member of this bitmap set,
-        call <literal>bms_is_member(attnum -
+        call <literal>bms_is_member(attphysnum -
         FirstLowInvalidHeapAttributeNumber,
         trigdata->tg_updatedcols))</literal>.
        </para>
diff --git a/doc/src/sgml/xaggr.sgml b/doc/src/sgml/xaggr.sgml
index bdad8d3dc2..b983149059 100644
--- a/doc/src/sgml/xaggr.sgml
+++ b/doc/src/sgml/xaggr.sgml
@@ -319,7 +319,7 @@ CREATE AGGREGATE array_accum (anycompatible)
 <programlisting>
 SELECT attrelid::regclass, array_accum(attname)
     FROM pg_attribute
-    WHERE attnum &gt; 0 AND attrelid = 'pg_tablespace'::regclass
+    WHERE attphysnum &gt; 0 AND attrelid = 'pg_tablespace'::regclass
     GROUP BY attrelid;
 
    attrelid    |              array_accum
@@ -329,7 +329,7 @@ SELECT attrelid::regclass, array_accum(attname)
 
 SELECT attrelid::regclass, array_accum(atttypid::regtype)
     FROM pg_attribute
-    WHERE attnum &gt; 0 AND attrelid = 'pg_tablespace'::regclass
+    WHERE attphysnum &gt; 0 AND attrelid = 'pg_tablespace'::regclass
     GROUP BY attrelid;
 
    attrelid    |        array_accum
diff --git a/src/backend/access/brin/brin_tuple.c b/src/backend/access/brin/brin_tuple.c
index c0e2dbd23b..f79840a357 100644
--- a/src/backend/access/brin/brin_tuple.c
+++ b/src/backend/access/brin/brin_tuple.c
@@ -634,7 +634,7 @@ brin_deconstruct_tuple(BrinDesc *brdesc,
 					   char *tp, bits8 *nullbits, bool nulls,
 					   Datum *values, bool *allnulls, bool *hasnulls)
 {
-	int			attnum;
+	int			attphysnum;
 	int			stored;
 	TupleDesc	diskdsc;
 	long		off;
@@ -645,14 +645,14 @@ brin_deconstruct_tuple(BrinDesc *brdesc,
 	 * 1 for a null value (rather than a 1 for a not null value as is the
 	 * att_isnull convention used elsewhere.)  See brin_form_tuple.
 	 */
-	for (attnum = 0; attnum < brdesc->bd_tupdesc->natts; attnum++)
+	for (attphysnum = 0; attphysnum < brdesc->bd_tupdesc->natts; attphysnum++)
 	{
 		/*
 		 * the "all nulls" bit means that all values in the page range for
 		 * this column are nulls.  Therefore there are no values in the tuple
 		 * data area.
 		 */
-		allnulls[attnum] = nulls && !att_isnull(attnum, nullbits);
+		allnulls[attphysnum] = nulls && !att_isnull(attphysnum, nullbits);
 
 		/*
 		 * the "has nulls" bit means that some tuples have nulls, but others
@@ -661,8 +661,8 @@ brin_deconstruct_tuple(BrinDesc *brdesc,
 		 *
 		 * The hasnulls bits follow the allnulls bits in the same bitmask.
 		 */
-		hasnulls[attnum] =
-			nulls && !att_isnull(brdesc->bd_tupdesc->natts + attnum, nullbits);
+		hasnulls[attphysnum] =
+			nulls && !att_isnull(brdesc->bd_tupdesc->natts + attphysnum, nullbits);
 	}
 
 	/*
@@ -673,18 +673,18 @@ brin_deconstruct_tuple(BrinDesc *brdesc,
 	diskdsc = brtuple_disk_tupdesc(brdesc);
 	stored = 0;
 	off = 0;
-	for (attnum = 0; attnum < brdesc->bd_tupdesc->natts; attnum++)
+	for (attphysnum = 0; attphysnum < brdesc->bd_tupdesc->natts; attphysnum++)
 	{
 		int			datumno;
 
-		if (allnulls[attnum])
+		if (allnulls[attphysnum])
 		{
-			stored += brdesc->bd_info[attnum]->oi_nstored;
+			stored += brdesc->bd_info[attphysnum]->oi_nstored;
 			continue;
 		}
 
 		for (datumno = 0;
-			 datumno < brdesc->bd_info[attnum]->oi_nstored;
+			 datumno < brdesc->bd_info[attphysnum]->oi_nstored;
 			 datumno++)
 		{
 			Form_pg_attribute thisatt = TupleDescAttr(diskdsc, stored);
diff --git a/src/backend/access/common/attmap.c b/src/backend/access/common/attmap.c
index 896f82a22b..d84b1bcdc4 100644
--- a/src/backend/access/common/attmap.c
+++ b/src/backend/access/common/attmap.c
@@ -231,7 +231,7 @@ build_attrmap_by_name(TupleDesc indesc,
 									   attname,
 									   format_type_be(outdesc->tdtypeid),
 									   format_type_be(indesc->tdtypeid))));
-				attrMap->attnums[i] = inatt->attnum;
+				attrMap->attnums[i] = inatt->attphysnum;
 				break;
 			}
 		}
diff --git a/src/backend/access/common/heaptuple.c b/src/backend/access/common/heaptuple.c
index 503cda46ef..4e61b6b372 100644
--- a/src/backend/access/common/heaptuple.c
+++ b/src/backend/access/common/heaptuple.c
@@ -82,14 +82,14 @@
  */
 Datum
 getmissingattr(TupleDesc tupleDesc,
-			   int attnum, bool *isnull)
+			   int attphysnum, bool *isnull)
 {
 	Form_pg_attribute att;
 
-	Assert(attnum <= tupleDesc->natts);
-	Assert(attnum > 0);
+	Assert(attphysnum <= tupleDesc->natts);
+	Assert(attphysnum > 0);
 
-	att = TupleDescAttr(tupleDesc, attnum - 1);
+	att = TupleDescAttr(tupleDesc, attphysnum - 1);
 
 	if (att->atthasmissing)
 	{
@@ -98,7 +98,7 @@ getmissingattr(TupleDesc tupleDesc,
 		Assert(tupleDesc->constr);
 		Assert(tupleDesc->constr->missing);
 
-		attrmiss = tupleDesc->constr->missing + (attnum - 1);
+		attrmiss = tupleDesc->constr->missing + (attphysnum - 1);
 
 		if (attrmiss->am_present)
 		{
@@ -356,29 +356,29 @@ heap_fill_tuple(TupleDesc tupleDesc,
  * ----------------
  */
 bool
-heap_attisnull(HeapTuple tup, int attnum, TupleDesc tupleDesc)
+heap_attisnull(HeapTuple tup, int attphysnum, TupleDesc tupleDesc)
 {
 	/*
 	 * We allow a NULL tupledesc for relations not expected to have missing
 	 * values, such as catalog relations and indexes.
 	 */
-	Assert(!tupleDesc || attnum <= tupleDesc->natts);
-	if (attnum > (int) HeapTupleHeaderGetNatts(tup->t_data))
+	Assert(!tupleDesc || attphysnum <= tupleDesc->natts);
+	if (attphysnum > (int) HeapTupleHeaderGetNatts(tup->t_data))
 	{
-		if (tupleDesc && TupleDescAttr(tupleDesc, attnum - 1)->atthasmissing)
+		if (tupleDesc && TupleDescAttr(tupleDesc, attphysnum - 1)->atthasmissing)
 			return false;
 		else
 			return true;
 	}
 
-	if (attnum > 0)
+	if (attphysnum > 0)
 	{
 		if (HeapTupleNoNulls(tup))
 			return false;
-		return att_isnull(attnum - 1, tup->t_data->t_bits);
+		return att_isnull(attphysnum - 1, tup->t_data->t_bits);
 	}
 
-	switch (attnum)
+	switch (attphysnum)
 	{
 		case TableOidAttributeNumber:
 		case SelfItemPointerAttributeNumber:
@@ -390,7 +390,7 @@ heap_attisnull(HeapTuple tup, int attnum, TupleDesc tupleDesc)
 			break;
 
 		default:
-			elog(ERROR, "invalid attnum: %d", attnum);
+			elog(ERROR, "invalid attphysnum: %d", attphysnum);
 	}
 
 	return false;
@@ -421,7 +421,7 @@ heap_attisnull(HeapTuple tup, int attnum, TupleDesc tupleDesc)
  */
 Datum
 nocachegetattr(HeapTuple tuple,
-			   int attnum,
+			   int attphysnum,
 			   TupleDesc tupleDesc)
 {
 	HeapTupleHeader tup = tuple->t_data;
@@ -439,7 +439,7 @@ nocachegetattr(HeapTuple tuple,
 	 * ----------------
 	 */
 
-	attnum--;
+	attphysnum--;
 
 	if (!HeapTupleNoNulls(tuple))
 	{
@@ -448,8 +448,8 @@ nocachegetattr(HeapTuple tuple,
 		 *
 		 * check to see if any preceding bits are null...
 		 */
-		int			byte = attnum >> 3;
-		int			finalbit = attnum & 0x07;
+		int			byte = attphysnum >> 3;
+		int			finalbit = attphysnum & 0x07;
 
 		/* check for nulls "before" final bit of last byte */
 		if ((~bp[byte]) & ((1 << finalbit) - 1))
@@ -480,7 +480,7 @@ nocachegetattr(HeapTuple tuple,
 		 * If we get here, there are no nulls up to and including the target
 		 * attribute.  If we have a cached offset, we can use it.
 		 */
-		att = TupleDescAttr(tupleDesc, attnum);
+		att = TupleDescAttr(tupleDesc, attphysnum);
 		if (att->attcacheoff >= 0)
 			return fetchatt(att, tp + att->attcacheoff);
 
@@ -493,7 +493,7 @@ nocachegetattr(HeapTuple tuple,
 		{
 			int			j;
 
-			for (j = 0; j <= attnum; j++)
+			for (j = 0; j <= attphysnum; j++)
 			{
 				if (TupleDescAttr(tupleDesc, j)->attlen <= 0)
 				{
@@ -541,9 +541,9 @@ nocachegetattr(HeapTuple tuple,
 			off += att->attlen;
 		}
 
-		Assert(j > attnum);
+		Assert(j > attphysnum);
 
-		off = TupleDescAttr(tupleDesc, attnum)->attcacheoff;
+		off = TupleDescAttr(tupleDesc, attphysnum)->attcacheoff;
 	}
 	else
 	{
@@ -601,7 +601,7 @@ nocachegetattr(HeapTuple tuple,
 					att->attcacheoff = off;
 			}
 
-			if (i == attnum)
+			if (i == attphysnum)
 				break;
 
 			off = att_addlength_pointer(off, att->attlen, tp + off);
@@ -611,7 +611,7 @@ nocachegetattr(HeapTuple tuple,
 		}
 	}
 
-	return fetchatt(TupleDescAttr(tupleDesc, attnum), tp + off);
+	return fetchatt(TupleDescAttr(tupleDesc, attphysnum), tp + off);
 }
 
 /* ----------------
@@ -620,11 +620,11 @@ nocachegetattr(HeapTuple tuple,
  *		Fetch the value of a system attribute for a tuple.
  *
  * This is a support routine for the heap_getattr macro.  The macro
- * has already determined that the attnum refers to a system attribute.
+ * has already determined that the attphysnum refers to a system attribute.
  * ----------------
  */
 Datum
-heap_getsysattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
+heap_getsysattr(HeapTuple tup, int attphysnum, TupleDesc tupleDesc, bool *isnull)
 {
 	Datum		result;
 
@@ -633,7 +633,7 @@ heap_getsysattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
 	/* Currently, no sys attribute ever reads as NULL. */
 	*isnull = false;
 
-	switch (attnum)
+	switch (attphysnum)
 	{
 		case SelfItemPointerAttributeNumber:
 			/* pass-by-reference datatype */
@@ -660,7 +660,7 @@ heap_getsysattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
 			result = ObjectIdGetDatum(tup->t_tableOid);
 			break;
 		default:
-			elog(ERROR, "invalid attnum: %d", attnum);
+			elog(ERROR, "invalid attphysnum: %d", attphysnum);
 			result = 0;			/* keep compiler quiet */
 			break;
 	}
@@ -735,7 +735,7 @@ expand_tuple(HeapTuple *targetHeapTuple,
 			 TupleDesc tupleDesc)
 {
 	AttrMissing *attrmiss = NULL;
-	int			attnum;
+	int			attphysnum;
 	int			firstmissingnum;
 	bool		hasNulls = HeapTupleHasNulls(sourceTuple);
 	HeapTupleHeader targetTHeader;
@@ -790,22 +790,22 @@ expand_tuple(HeapTuple *targetHeapTuple,
 		 * Now walk the missing attributes. If there is a missing value make
 		 * space for it. Otherwise, it's going to be NULL.
 		 */
-		for (attnum = firstmissingnum;
-			 attnum < natts;
-			 attnum++)
+		for (attphysnum = firstmissingnum;
+			 attphysnum < natts;
+			 attphysnum++)
 		{
-			if (attrmiss[attnum].am_present)
+			if (attrmiss[attphysnum].am_present)
 			{
-				Form_pg_attribute att = TupleDescAttr(tupleDesc, attnum);
+				Form_pg_attribute att = TupleDescAttr(tupleDesc, attphysnum);
 
 				targetDataLen = att_align_datum(targetDataLen,
 												att->attalign,
 												att->attlen,
-												attrmiss[attnum].am_value);
+												attrmiss[attphysnum].am_value);
 
 				targetDataLen = att_addlength_pointer(targetDataLen,
 													  att->attlen,
-													  attrmiss[attnum].am_value);
+													  attrmiss[attphysnum].am_value);
 			}
 			else
 			{
@@ -922,19 +922,19 @@ expand_tuple(HeapTuple *targetHeapTuple,
 	targetData += sourceDataLen;
 
 	/* Now fill in the missing values */
-	for (attnum = sourceNatts; attnum < natts; attnum++)
+	for (attphysnum = sourceNatts; attphysnum < natts; attphysnum++)
 	{
 
-		Form_pg_attribute attr = TupleDescAttr(tupleDesc, attnum);
+		Form_pg_attribute attr = TupleDescAttr(tupleDesc, attphysnum);
 
-		if (attrmiss && attrmiss[attnum].am_present)
+		if (attrmiss && attrmiss[attphysnum].am_present)
 		{
 			fill_val(attr,
 					 nullBits ? &nullBits : NULL,
 					 &bitMask,
 					 &targetData,
 					 infoMask,
-					 attrmiss[attnum].am_value,
+					 attrmiss[attphysnum].am_value,
 					 false);
 		}
 		else
@@ -1202,12 +1202,12 @@ heap_modify_tuple_by_cols(HeapTuple tuple,
 
 	for (i = 0; i < nCols; i++)
 	{
-		int			attnum = replCols[i];
+		int			attphysnum = replCols[i];
 
-		if (attnum <= 0 || attnum > numberOfAttributes)
-			elog(ERROR, "invalid column number %d", attnum);
-		values[attnum - 1] = replValues[i];
-		isnull[attnum - 1] = replIsnull[i];
+		if (attphysnum <= 0 || attphysnum > numberOfAttributes)
+			elog(ERROR, "invalid column number %d", attphysnum);
+		values[attphysnum - 1] = replValues[i];
+		isnull[attphysnum - 1] = replIsnull[i];
 	}
 
 	/*
@@ -1253,7 +1253,7 @@ heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc,
 	bool		hasnulls = HeapTupleHasNulls(tuple);
 	int			tdesc_natts = tupleDesc->natts;
 	int			natts;			/* number of atts to extract */
-	int			attnum;
+	int			attphysnum;
 	char	   *tp;				/* ptr to tuple data */
 	uint32		off;			/* offset in tuple data */
 	bits8	   *bp = tup->t_bits;	/* ptr to null bitmap in tuple */
@@ -1272,19 +1272,19 @@ heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc,
 
 	off = 0;
 
-	for (attnum = 0; attnum < natts; attnum++)
+	for (attphysnum = 0; attphysnum < natts; attphysnum++)
 	{
-		Form_pg_attribute thisatt = TupleDescAttr(tupleDesc, attnum);
+		Form_pg_attribute thisatt = TupleDescAttr(tupleDesc, attphysnum);
 
-		if (hasnulls && att_isnull(attnum, bp))
+		if (hasnulls && att_isnull(attphysnum, bp))
 		{
-			values[attnum] = (Datum) 0;
-			isnull[attnum] = true;
+			values[attphysnum] = (Datum) 0;
+			isnull[attphysnum] = true;
 			slow = true;		/* can't use attcacheoff anymore */
 			continue;
 		}
 
-		isnull[attnum] = false;
+		isnull[attphysnum] = false;
 
 		if (!slow && thisatt->attcacheoff >= 0)
 			off = thisatt->attcacheoff;
@@ -1315,7 +1315,7 @@ heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc,
 				thisatt->attcacheoff = off;
 		}
 
-		values[attnum] = fetchatt(thisatt, tp + off);
+		values[attphysnum] = fetchatt(thisatt, tp + off);
 
 		off = att_addlength_pointer(off, thisatt->attlen, tp + off);
 
@@ -1327,8 +1327,8 @@ heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc,
 	 * If tuple doesn't have all the atts indicated by tupleDesc, read the
 	 * rest as nulls or missing values as appropriate.
 	 */
-	for (; attnum < tdesc_natts; attnum++)
-		values[attnum] = getmissingattr(tupleDesc, attnum + 1, &isnull[attnum]);
+	for (; attphysnum < tdesc_natts; attphysnum++)
+		values[attphysnum] = getmissingattr(tupleDesc, attphysnum + 1, &isnull[attphysnum]);
 }
 
 /*
diff --git a/src/backend/access/common/indextuple.c b/src/backend/access/common/indextuple.c
index 3065730bae..126bc93e1c 100644
--- a/src/backend/access/common/indextuple.c
+++ b/src/backend/access/common/indextuple.c
@@ -220,7 +220,7 @@ index_form_tuple(TupleDesc tupleDescriptor,
  */
 Datum
 nocache_index_getattr(IndexTuple tup,
-					  int attnum,
+					  int attphysnum,
 					  TupleDesc tupleDesc)
 {
 	char	   *tp;				/* ptr to data part of tuple */
@@ -240,7 +240,7 @@ nocache_index_getattr(IndexTuple tup,
 
 	data_off = IndexInfoFindDataOffset(tup->t_info);
 
-	attnum--;
+	attphysnum--;
 
 	if (IndexTupleHasNulls(tup))
 	{
@@ -257,8 +257,8 @@ nocache_index_getattr(IndexTuple tup,
 		 * Now check to see if any preceding bits are null...
 		 */
 		{
-			int			byte = attnum >> 3;
-			int			finalbit = attnum & 0x07;
+			int			byte = attphysnum >> 3;
+			int			finalbit = attphysnum & 0x07;
 
 			/* check for nulls "before" final bit of last byte */
 			if ((~bp[byte]) & ((1 << finalbit) - 1))
@@ -290,7 +290,7 @@ nocache_index_getattr(IndexTuple tup,
 		 * If we get here, there are no nulls up to and including the target
 		 * attribute.  If we have a cached offset, we can use it.
 		 */
-		att = TupleDescAttr(tupleDesc, attnum);
+		att = TupleDescAttr(tupleDesc, attphysnum);
 		if (att->attcacheoff >= 0)
 			return fetchatt(att, tp + att->attcacheoff);
 
@@ -303,7 +303,7 @@ nocache_index_getattr(IndexTuple tup,
 		{
 			int			j;
 
-			for (j = 0; j <= attnum; j++)
+			for (j = 0; j <= attphysnum; j++)
 			{
 				if (TupleDescAttr(tupleDesc, j)->attlen <= 0)
 				{
@@ -351,9 +351,9 @@ nocache_index_getattr(IndexTuple tup,
 			off += att->attlen;
 		}
 
-		Assert(j > attnum);
+		Assert(j > attphysnum);
 
-		off = TupleDescAttr(tupleDesc, attnum)->attcacheoff;
+		off = TupleDescAttr(tupleDesc, attphysnum)->attcacheoff;
 	}
 	else
 	{
@@ -411,7 +411,7 @@ nocache_index_getattr(IndexTuple tup,
 					att->attcacheoff = off;
 			}
 
-			if (i == attnum)
+			if (i == attphysnum)
 				break;
 
 			off = att_addlength_pointer(off, att->attlen, tp + off);
@@ -421,7 +421,7 @@ nocache_index_getattr(IndexTuple tup,
 		}
 	}
 
-	return fetchatt(TupleDescAttr(tupleDesc, attnum), tp + off);
+	return fetchatt(TupleDescAttr(tupleDesc, attphysnum), tp + off);
 }
 
 /*
@@ -462,26 +462,26 @@ index_deform_tuple_internal(TupleDesc tupleDescriptor,
 							char *tp, bits8 *bp, int hasnulls)
 {
 	int			natts = tupleDescriptor->natts; /* number of atts to extract */
-	int			attnum;
+	int			attphysnum;
 	int			off = 0;		/* offset in tuple data */
 	bool		slow = false;	/* can we use/set attcacheoff? */
 
 	/* Assert to protect callers who allocate fixed-size arrays */
 	Assert(natts <= INDEX_MAX_KEYS);
 
-	for (attnum = 0; attnum < natts; attnum++)
+	for (attphysnum = 0; attphysnum < natts; attphysnum++)
 	{
-		Form_pg_attribute thisatt = TupleDescAttr(tupleDescriptor, attnum);
+		Form_pg_attribute thisatt = TupleDescAttr(tupleDescriptor, attphysnum);
 
-		if (hasnulls && att_isnull(attnum, bp))
+		if (hasnulls && att_isnull(attphysnum, bp))
 		{
-			values[attnum] = (Datum) 0;
-			isnull[attnum] = true;
+			values[attphysnum] = (Datum) 0;
+			isnull[attphysnum] = true;
 			slow = true;		/* can't use attcacheoff anymore */
 			continue;
 		}
 
-		isnull[attnum] = false;
+		isnull[attphysnum] = false;
 
 		if (!slow && thisatt->attcacheoff >= 0)
 			off = thisatt->attcacheoff;
@@ -512,7 +512,7 @@ index_deform_tuple_internal(TupleDesc tupleDescriptor,
 				thisatt->attcacheoff = off;
 		}
 
-		values[attnum] = fetchatt(thisatt, tp + off);
+		values[attphysnum] = fetchatt(thisatt, tp + off);
 
 		off = att_addlength_pointer(off, thisatt->attlen, tp + off);
 
diff --git a/src/backend/access/common/printsimple.c b/src/backend/access/common/printsimple.c
index e99aa279f6..8c8b85ed63 100644
--- a/src/backend/access/common/printsimple.c
+++ b/src/backend/access/common/printsimple.c
@@ -41,7 +41,7 @@ printsimple_startup(DestReceiver *self, int operation, TupleDesc tupdesc)
 
 		pq_sendstring(&buf, NameStr(attr->attname));
 		pq_sendint32(&buf, 0);	/* table oid */
-		pq_sendint16(&buf, 0);	/* attnum */
+		pq_sendint16(&buf, 0);	/* attphysnum */
 		pq_sendint32(&buf, (int) attr->atttypid);
 		pq_sendint16(&buf, attr->attlen);
 		pq_sendint32(&buf, attr->atttypmod);
diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c
index 9f41b1e854..409a93ccdf 100644
--- a/src/backend/access/common/tupdesc.c
+++ b/src/backend/access/common/tupdesc.c
@@ -291,7 +291,7 @@ TupleDescCopyEntry(TupleDesc dst, AttrNumber dstAttno,
 	 * by other uses of this function or TupleDescInitEntry.  So we cheat a
 	 * bit to avoid a useless O(N^2) penalty.
 	 */
-	dstAtt->attnum = dstAttno;
+	dstAtt->attphysnum = dstAttno;
 	dstAtt->attcacheoff = -1;
 
 	/* since we're not copying constraints or defaults, clear these */
@@ -416,7 +416,7 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2)
 
 		/*
 		 * We do not need to check every single field here: we can disregard
-		 * attrelid and attnum (which were used to place the row in the attrs
+		 * attrelid and attphysnum (which were used to place the row in the attrs
 		 * array in the first place).  It might look like we could dispense
 		 * with checking attlen/attbyval/attalign, since these are derived
 		 * from atttypid; but in the case of dropped columns we must check
@@ -619,7 +619,7 @@ TupleDescInitEntry(TupleDesc desc,
 	att->attcacheoff = -1;
 	att->atttypmod = typmod;
 
-	att->attnum = attributeNumber;
+	att->attphysnum = attributeNumber;
 	att->attndims = attdim;
 
 	att->attnotnull = false;
@@ -680,7 +680,7 @@ TupleDescInitBuiltinEntry(TupleDesc desc,
 	att->attcacheoff = -1;
 	att->atttypmod = typmod;
 
-	att->attnum = attributeNumber;
+	att->attphysnum = attributeNumber;
 	att->attndims = attdim;
 
 	att->attnotnull = false;
@@ -777,7 +777,7 @@ TupleDesc
 BuildDescForRelation(List *schema)
 {
 	int			natts;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	ListCell   *l;
 	TupleDesc	desc;
 	bool		has_not_null;
@@ -794,7 +794,7 @@ BuildDescForRelation(List *schema)
 	desc = CreateTemplateTupleDesc(natts);
 	has_not_null = false;
 
-	attnum = 0;
+	attphysnum = 0;
 
 	foreach(l, schema)
 	{
@@ -807,7 +807,7 @@ BuildDescForRelation(List *schema)
 		 * the list and have TupleDescInitEntry fill in the attribute
 		 * information we need.
 		 */
-		attnum++;
+		attphysnum++;
 
 		attname = entry->colname;
 		typenameTypeIdAndMod(NULL, entry->typeName, &atttypid, &atttypmod);
@@ -825,12 +825,12 @@ BuildDescForRelation(List *schema)
 					 errmsg("column \"%s\" cannot be declared SETOF",
 							attname)));
 
-		TupleDescInitEntry(desc, attnum, attname,
+		TupleDescInitEntry(desc, attphysnum, attname,
 						   atttypid, atttypmod, attdim);
-		att = TupleDescAttr(desc, attnum - 1);
+		att = TupleDescAttr(desc, attphysnum - 1);
 
 		/* Override TupleDescInitEntry's settings as requested */
-		TupleDescInitEntryCollation(desc, attnum, attcollation);
+		TupleDescInitEntryCollation(desc, attphysnum, attcollation);
 		if (entry->storage)
 			att->attstorage = entry->storage;
 
@@ -877,7 +877,7 @@ TupleDesc
 BuildDescFromLists(List *names, List *types, List *typmods, List *collations)
 {
 	int			natts;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	ListCell   *l1;
 	ListCell   *l2;
 	ListCell   *l3;
@@ -894,7 +894,7 @@ BuildDescFromLists(List *names, List *types, List *typmods, List *collations)
 	 */
 	desc = CreateTemplateTupleDesc(natts);
 
-	attnum = 0;
+	attphysnum = 0;
 	forfour(l1, names, l2, types, l3, typmods, l4, collations)
 	{
 		char	   *attname = strVal(lfirst(l1));
@@ -902,10 +902,10 @@ BuildDescFromLists(List *names, List *types, List *typmods, List *collations)
 		int32		atttypmod = lfirst_int(l3);
 		Oid			attcollation = lfirst_oid(l4);
 
-		attnum++;
+		attphysnum++;
 
-		TupleDescInitEntry(desc, attnum, attname, atttypid, atttypmod, 0);
-		TupleDescInitEntryCollation(desc, attnum, attcollation);
+		TupleDescInitEntry(desc, attphysnum, attname, atttypid, atttypmod, 0);
+		TupleDescInitEntryCollation(desc, attphysnum, attcollation);
 	}
 
 	return desc;
diff --git a/src/backend/access/gin/ginbulk.c b/src/backend/access/gin/ginbulk.c
index 0d0da44694..2ce4301250 100644
--- a/src/backend/access/gin/ginbulk.c
+++ b/src/backend/access/gin/ginbulk.c
@@ -76,8 +76,8 @@ cmpEntryAccumulator(const RBTNode *a, const RBTNode *b, void *arg)
 	BuildAccumulator *accum = (BuildAccumulator *) arg;
 
 	return ginCompareAttEntries(accum->ginstate,
-								ea->attnum, ea->key, ea->category,
-								eb->attnum, eb->key, eb->category);
+								ea->attphysnum, ea->key, ea->category,
+								eb->attphysnum, eb->key, eb->category);
 }
 
 /* Allocator function for rbtree.c */
@@ -125,12 +125,12 @@ ginInitBA(BuildAccumulator *accum)
  * palloc'd space in accum->allocatedMemory.
  */
 static Datum
-getDatumCopy(BuildAccumulator *accum, OffsetNumber attnum, Datum value)
+getDatumCopy(BuildAccumulator *accum, OffsetNumber attphysnum, Datum value)
 {
 	Form_pg_attribute att;
 	Datum		res;
 
-	att = TupleDescAttr(accum->ginstate->origTupdesc, attnum - 1);
+	att = TupleDescAttr(accum->ginstate->origTupdesc, attphysnum - 1);
 	if (att->attbyval)
 		res = value;
 	else
@@ -146,7 +146,7 @@ getDatumCopy(BuildAccumulator *accum, OffsetNumber attnum, Datum value)
  */
 static void
 ginInsertBAEntry(BuildAccumulator *accum,
-				 ItemPointer heapptr, OffsetNumber attnum,
+				 ItemPointer heapptr, OffsetNumber attphysnum,
 				 Datum key, GinNullCategory category)
 {
 	GinEntryAccumulator eatmp;
@@ -157,7 +157,7 @@ ginInsertBAEntry(BuildAccumulator *accum,
 	 * For the moment, fill only the fields of eatmp that will be looked at by
 	 * cmpEntryAccumulator or ginCombineData.
 	 */
-	eatmp.attnum = attnum;
+	eatmp.attphysnum = attphysnum;
 	eatmp.key = key;
 	eatmp.category = category;
 	/* temporarily set up single-entry itempointer list */
@@ -173,7 +173,7 @@ ginInsertBAEntry(BuildAccumulator *accum,
 		 * copies of the datum (if it's not null) and itempointer.
 		 */
 		if (category == GIN_CAT_NORM_KEY)
-			ea->key = getDatumCopy(accum, attnum, key);
+			ea->key = getDatumCopy(accum, attphysnum, key);
 		ea->maxcount = DEF_NPTR;
 		ea->count = 1;
 		ea->shouldSort = false;
@@ -208,7 +208,7 @@ ginInsertBAEntry(BuildAccumulator *accum,
  */
 void
 ginInsertBAEntries(BuildAccumulator *accum,
-				   ItemPointer heapptr, OffsetNumber attnum,
+				   ItemPointer heapptr, OffsetNumber attphysnum,
 				   Datum *entries, GinNullCategory *categories,
 				   int32 nentries)
 {
@@ -217,7 +217,7 @@ ginInsertBAEntries(BuildAccumulator *accum,
 	if (nentries <= 0)
 		return;
 
-	Assert(ItemPointerIsValid(heapptr) && attnum >= FirstOffsetNumber);
+	Assert(ItemPointerIsValid(heapptr) && attphysnum >= FirstOffsetNumber);
 
 	/*
 	 * step will contain largest power of 2 and <= nentries
@@ -235,7 +235,7 @@ ginInsertBAEntries(BuildAccumulator *accum,
 		int			i;
 
 		for (i = step - 1; i < nentries && i >= 0; i += step << 1 /* *2 */ )
-			ginInsertBAEntry(accum, heapptr, attnum,
+			ginInsertBAEntry(accum, heapptr, attphysnum,
 							 entries[i], categories[i]);
 
 		step >>= 1;				/* /2 */
@@ -266,7 +266,7 @@ ginBeginBAScan(BuildAccumulator *accum)
  */
 ItemPointerData *
 ginGetBAEntry(BuildAccumulator *accum,
-			  OffsetNumber *attnum, Datum *key, GinNullCategory *category,
+			  OffsetNumber *attphysnum, Datum *key, GinNullCategory *category,
 			  uint32 *n)
 {
 	GinEntryAccumulator *entry;
@@ -277,7 +277,7 @@ ginGetBAEntry(BuildAccumulator *accum,
 	if (entry == NULL)
 		return NULL;			/* no more entries */
 
-	*attnum = entry->attnum;
+	*attphysnum = entry->attphysnum;
 	*key = entry->key;
 	*category = entry->category;
 	list = entry->list;
diff --git a/src/backend/access/gin/ginentrypage.c b/src/backend/access/gin/ginentrypage.c
index 382f8bb4d6..3b6c2300a3 100644
--- a/src/backend/access/gin/ginentrypage.c
+++ b/src/backend/access/gin/ginentrypage.c
@@ -43,7 +43,7 @@ static void entrySplitPage(GinBtree btree, Buffer origbuf,
  */
 IndexTuple
 GinFormTuple(GinState *ginstate,
-			 OffsetNumber attnum, Datum key, GinNullCategory category,
+			 OffsetNumber attphysnum, Datum key, GinNullCategory category,
 			 Pointer data, Size dataSize, int nipd,
 			 bool errorTooBig)
 {
@@ -60,13 +60,13 @@ GinFormTuple(GinState *ginstate,
 	}
 	else
 	{
-		datums[0] = UInt16GetDatum(attnum);
+		datums[0] = UInt16GetDatum(attphysnum);
 		isnull[0] = false;
 		datums[1] = key;
 		isnull[1] = (category != GIN_CAT_NORM_KEY);
 	}
 
-	itup = index_form_tuple(ginstate->tupdesc[attnum - 1], datums, isnull);
+	itup = index_form_tuple(ginstate->tupdesc[attphysnum - 1], datums, isnull);
 
 	/*
 	 * Determine and store offset to the posting list, making sure there is
@@ -160,7 +160,7 @@ GinFormTuple(GinState *ginstate,
  * in *nitems.
  */
 ItemPointer
-ginReadTuple(GinState *ginstate, OffsetNumber attnum, IndexTuple itup,
+ginReadTuple(GinState *ginstate, OffsetNumber attphysnum, IndexTuple itup,
 			 int *nitems)
 {
 	Pointer		ptr = GinGetPosting(itup);
@@ -244,7 +244,7 @@ static bool
 entryIsMoveRight(GinBtree btree, Page page)
 {
 	IndexTuple	itup;
-	OffsetNumber attnum;
+	OffsetNumber attphysnum;
 	Datum		key;
 	GinNullCategory category;
 
@@ -252,12 +252,12 @@ entryIsMoveRight(GinBtree btree, Page page)
 		return false;
 
 	itup = getRightMostTuple(page);
-	attnum = gintuple_get_attrnum(btree->ginstate, itup);
+	attphysnum = gintuple_get_attrnum(btree->ginstate, itup);
 	key = gintuple_get_key(btree->ginstate, itup, &category);
 
 	if (ginCompareAttEntries(btree->ginstate,
 							 btree->entryAttnum, btree->entryKey, btree->entryCategory,
-							 attnum, key, category) > 0)
+							 attphysnum, key, category) > 0)
 		return true;
 
 	return false;
@@ -304,18 +304,18 @@ entryLocateEntry(GinBtree btree, GinBtreeStack *stack)
 		}
 		else
 		{
-			OffsetNumber attnum;
+			OffsetNumber attphysnum;
 			Datum		key;
 			GinNullCategory category;
 
 			itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, mid));
-			attnum = gintuple_get_attrnum(btree->ginstate, itup);
+			attphysnum = gintuple_get_attrnum(btree->ginstate, itup);
 			key = gintuple_get_key(btree->ginstate, itup, &category);
 			result = ginCompareAttEntries(btree->ginstate,
 										  btree->entryAttnum,
 										  btree->entryKey,
 										  btree->entryCategory,
-										  attnum, key, category);
+										  attphysnum, key, category);
 		}
 
 		if (result == 0)
@@ -374,19 +374,19 @@ entryLocateLeafEntry(GinBtree btree, GinBtreeStack *stack)
 	{
 		OffsetNumber mid = low + ((high - low) / 2);
 		IndexTuple	itup;
-		OffsetNumber attnum;
+		OffsetNumber attphysnum;
 		Datum		key;
 		GinNullCategory category;
 		int			result;
 
 		itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, mid));
-		attnum = gintuple_get_attrnum(btree->ginstate, itup);
+		attphysnum = gintuple_get_attrnum(btree->ginstate, itup);
 		key = gintuple_get_key(btree->ginstate, itup, &category);
 		result = ginCompareAttEntries(btree->ginstate,
 									  btree->entryAttnum,
 									  btree->entryKey,
 									  btree->entryCategory,
-									  attnum, key, category);
+									  attphysnum, key, category);
 		if (result == 0)
 		{
 			stack->off = mid;
@@ -742,7 +742,7 @@ ginEntryFillRoot(GinBtree btree, Page root,
  * other than a faked-up Relation pointer; the key datum is bogus too.
  */
 void
-ginPrepareEntryScan(GinBtree btree, OffsetNumber attnum,
+ginPrepareEntryScan(GinBtree btree, OffsetNumber attphysnum,
 					Datum key, GinNullCategory category,
 					GinState *ginstate)
 {
@@ -766,7 +766,7 @@ ginPrepareEntryScan(GinBtree btree, OffsetNumber attnum,
 	btree->fullScan = false;
 	btree->isBuild = false;
 
-	btree->entryAttnum = attnum;
+	btree->entryAttnum = attphysnum;
 	btree->entryKey = key;
 	btree->entryCategory = category;
 }
diff --git a/src/backend/access/gin/ginfast.c b/src/backend/access/gin/ginfast.c
index 7409fdc165..2a50a55fbc 100644
--- a/src/backend/access/gin/ginfast.c
+++ b/src/backend/access/gin/ginfast.c
@@ -473,7 +473,7 @@ ginHeapTupleFastInsert(GinState *ginstate, GinTupleCollector *collector)
 void
 ginHeapTupleFastCollect(GinState *ginstate,
 						GinTupleCollector *collector,
-						OffsetNumber attnum, Datum value, bool isNull,
+						OffsetNumber attphysnum, Datum value, bool isNull,
 						ItemPointer ht_ctid)
 {
 	Datum	   *entries;
@@ -484,7 +484,7 @@ ginHeapTupleFastCollect(GinState *ginstate,
 	/*
 	 * Extract the key values that need to be inserted in the index
 	 */
-	entries = ginExtractEntries(ginstate, attnum, value, isNull,
+	entries = ginExtractEntries(ginstate, attphysnum, value, isNull,
 								&nentries, &categories);
 
 	/*
@@ -527,7 +527,7 @@ ginHeapTupleFastCollect(GinState *ginstate,
 	{
 		IndexTuple	itup;
 
-		itup = GinFormTuple(ginstate, attnum, entries[i], categories[i],
+		itup = GinFormTuple(ginstate, attphysnum, entries[i], categories[i],
 							NULL, 0, 0, true);
 		itup->t_tid = *ht_ctid;
 		collector->tuples[collector->ntuples++] = itup;
@@ -723,7 +723,7 @@ processPendingPage(BuildAccumulator *accum, KeyArray *ka,
 		Datum		curkey;
 		GinNullCategory curcategory;
 
-		/* Check for change of heap TID or attnum */
+		/* Check for change of heap TID or attphysnum */
 		curattnum = gintuple_get_attrnum(accum->ginstate, itup);
 
 		if (!ItemPointerIsValid(&heapptr))
@@ -902,7 +902,7 @@ ginInsertCleanup(GinState *ginstate, bool full_clean,
 			Datum		key;
 			GinNullCategory category;
 			OffsetNumber maxoff,
-						attnum;
+						attphysnum;
 
 			/*
 			 * Unlock current page to increase performance. Changes of page
@@ -919,9 +919,9 @@ ginInsertCleanup(GinState *ginstate, bool full_clean,
 			 */
 			ginBeginBAScan(&accum);
 			while ((list = ginGetBAEntry(&accum,
-										 &attnum, &key, &category, &nlist)) != NULL)
+										 &attphysnum, &key, &category, &nlist)) != NULL)
 			{
-				ginEntryInsert(ginstate, attnum, key, category,
+				ginEntryInsert(ginstate, attphysnum, key, category,
 							   list, nlist, NULL);
 				vacuum_delay_point();
 			}
@@ -949,8 +949,8 @@ ginInsertCleanup(GinState *ginstate, bool full_clean,
 
 				ginBeginBAScan(&accum);
 				while ((list = ginGetBAEntry(&accum,
-											 &attnum, &key, &category, &nlist)) != NULL)
-					ginEntryInsert(ginstate, attnum, key, category,
+											 &attphysnum, &key, &category, &nlist)) != NULL)
+					ginEntryInsert(ginstate, attphysnum, key, category,
 								   list, nlist, NULL);
 			}
 
diff --git a/src/backend/access/gin/ginget.c b/src/backend/access/gin/ginget.c
index fc85ba99ac..55f05eb65d 100644
--- a/src/backend/access/gin/ginget.c
+++ b/src/backend/access/gin/ginget.c
@@ -111,9 +111,9 @@ scanPostingTree(Relation index, GinScanEntry scanEntry,
  * 1. Partial-match support: scan from current point until the
  *	  comparePartialFn says we're done.
  * 2. SEARCH_MODE_ALL: scan from current point (which should be first
- *	  key for the current attnum) until we hit null items or end of attnum
+ *	  key for the current attphysnum) until we hit null items or end of attphysnum
  * 3. SEARCH_MODE_EVERYTHING: scan from current point (which should be first
- *	  key for the current attnum) until we hit end of attnum
+ *	  key for the current attphysnum) until we hit end of attphysnum
  *
  * Returns true if done, false if it's necessary to restart scan from scratch
  */
@@ -121,7 +121,7 @@ static bool
 collectMatchBitmap(GinBtreeData *btree, GinBtreeStack *stack,
 				   GinScanEntry scanEntry, Snapshot snapshot)
 {
-	OffsetNumber attnum;
+	OffsetNumber attphysnum;
 	Form_pg_attribute attr;
 
 	/* Initialize empty bitmap result */
@@ -133,8 +133,8 @@ collectMatchBitmap(GinBtreeData *btree, GinBtreeStack *stack,
 		return true;
 
 	/* Locate tupdesc entry for key column (for attbyval/attlen data) */
-	attnum = scanEntry->attnum;
-	attr = TupleDescAttr(btree->ginstate->origTupdesc, attnum - 1);
+	attphysnum = scanEntry->attphysnum;
+	attr = TupleDescAttr(btree->ginstate->origTupdesc, attphysnum - 1);
 
 	/*
 	 * Predicate lock entry leaf page, following pages will be locked by
@@ -162,7 +162,7 @@ collectMatchBitmap(GinBtreeData *btree, GinBtreeStack *stack,
 		/*
 		 * If tuple stores another attribute then stop scan
 		 */
-		if (gintuple_get_attrnum(btree->ginstate, itup) != attnum)
+		if (gintuple_get_attrnum(btree->ginstate, itup) != attphysnum)
 			return true;
 
 		/* Safe to fetch attribute value */
@@ -189,8 +189,8 @@ collectMatchBitmap(GinBtreeData *btree, GinBtreeStack *stack,
 			 * case cmp < 0 => not match and continue scan
 			 *----------
 			 */
-			cmp = DatumGetInt32(FunctionCall4Coll(&btree->ginstate->comparePartialFn[attnum - 1],
-												  btree->ginstate->supportCollation[attnum - 1],
+			cmp = DatumGetInt32(FunctionCall4Coll(&btree->ginstate->comparePartialFn[attphysnum - 1],
+												  btree->ginstate->supportCollation[attphysnum - 1],
 												  scanEntry->queryKey,
 												  idatum,
 												  UInt16GetDatum(scanEntry->strategy),
@@ -209,7 +209,7 @@ collectMatchBitmap(GinBtreeData *btree, GinBtreeStack *stack,
 			/*
 			 * In ALL mode, we are not interested in null items, so we can
 			 * stop if we get to a null-item placeholder (which will be the
-			 * last entry for a given attnum).  We do want to include NULL_KEY
+			 * last entry for a given attphysnum).  We do want to include NULL_KEY
 			 * and EMPTY_ITEM entries, though.
 			 */
 			if (icategory == GIN_CAT_NULL_ITEM)
@@ -274,7 +274,7 @@ collectMatchBitmap(GinBtreeData *btree, GinBtreeStack *stack,
 				page = BufferGetPage(stack->buffer);
 				itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, stack->off));
 
-				if (gintuple_get_attrnum(btree->ginstate, itup) == attnum)
+				if (gintuple_get_attrnum(btree->ginstate, itup) == attphysnum)
 				{
 					Datum		newDatum;
 					GinNullCategory newCategory;
@@ -282,7 +282,7 @@ collectMatchBitmap(GinBtreeData *btree, GinBtreeStack *stack,
 					newDatum = gintuple_get_key(btree->ginstate, itup,
 												&newCategory);
 
-					if (ginCompareEntries(btree->ginstate, attnum,
+					if (ginCompareEntries(btree->ginstate, attphysnum,
 										  newDatum, newCategory,
 										  idatum, icategory) == 0)
 						break;	/* Found! */
@@ -299,7 +299,7 @@ collectMatchBitmap(GinBtreeData *btree, GinBtreeStack *stack,
 			ItemPointer ipd;
 			int			nipd;
 
-			ipd = ginReadTuple(btree->ginstate, scanEntry->attnum, itup, &nipd);
+			ipd = ginReadTuple(btree->ginstate, scanEntry->attphysnum, itup, &nipd);
 			tbm_add_tuples(scanEntry->matchBitmap, ipd, nipd, false);
 			scanEntry->predictNumberResult += GinGetNPosting(itup);
 			pfree(ipd);
@@ -340,7 +340,7 @@ restartScanEntry:
 	 * we should find entry, and begin scan of posting tree or just store
 	 * posting list in memory
 	 */
-	ginPrepareEntryScan(&btreeEntry, entry->attnum,
+	ginPrepareEntryScan(&btreeEntry, entry->attphysnum,
 						entry->queryKey, entry->queryCategory,
 						ginstate);
 	stackEntry = ginFindLeafPage(&btreeEntry, true, false, snapshot);
@@ -457,7 +457,7 @@ restartScanEntry:
 							  snapshot);
 			if (GinGetNPosting(itup) > 0)
 			{
-				entry->list = ginReadTuple(ginstate, entry->attnum, itup,
+				entry->list = ginReadTuple(ginstate, entry->attphysnum, itup,
 										   &entry->nlist);
 				entry->predictNumberResult = entry->nlist;
 
@@ -1553,7 +1553,7 @@ matchPartialInPendingList(GinState *ginstate, Page page,
 	{
 		itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, off));
 
-		if (gintuple_get_attrnum(ginstate, itup) != entry->attnum)
+		if (gintuple_get_attrnum(ginstate, itup) != entry->attphysnum)
 			return false;
 
 		if (datumExtracted[off - 1] == false)
@@ -1574,8 +1574,8 @@ matchPartialInPendingList(GinState *ginstate, Page page,
 		 * case cmp < 0 => not match and continue scan
 		 *----------
 		 */
-		cmp = DatumGetInt32(FunctionCall4Coll(&ginstate->comparePartialFn[entry->attnum - 1],
-											  ginstate->supportCollation[entry->attnum - 1],
+		cmp = DatumGetInt32(FunctionCall4Coll(&ginstate->comparePartialFn[entry->attphysnum - 1],
+											  ginstate->supportCollation[entry->attphysnum - 1],
 											  entry->queryKey,
 											  datum[off - 1],
 											  UInt16GetDatum(entry->strategy),
@@ -1658,7 +1658,7 @@ collectMatchesForHeapRow(IndexScanDesc scan, pendingPosition *pos)
 
 				/*
 				 * Interesting tuples are from pos->firstOffset to
-				 * pos->lastOffset and they are ordered by (attnum, Datum) as
+				 * pos->lastOffset and they are ordered by (attphysnum, Datum) as
 				 * it's done in entry tree.  So we can use binary search to
 				 * avoid linear scanning.
 				 */
@@ -1672,12 +1672,12 @@ collectMatchesForHeapRow(IndexScanDesc scan, pendingPosition *pos)
 
 					attrnum = gintuple_get_attrnum(&so->ginstate, itup);
 
-					if (key->attnum < attrnum)
+					if (key->attphysnum < attrnum)
 					{
 						StopHigh = StopMiddle;
 						continue;
 					}
-					if (key->attnum > attrnum)
+					if (key->attphysnum > attrnum)
 					{
 						StopLow = StopMiddle + 1;
 						continue;
@@ -1711,7 +1711,7 @@ collectMatchesForHeapRow(IndexScanDesc scan, pendingPosition *pos)
 					else
 					{
 						res = ginCompareEntries(&so->ginstate,
-												entry->attnum,
+												entry->attphysnum,
 												entry->queryKey,
 												entry->queryCategory,
 												datum[StopMiddle - 1],
diff --git a/src/backend/access/gin/gininsert.c b/src/backend/access/gin/gininsert.c
index ea1c4184fb..a25ee278a5 100644
--- a/src/backend/access/gin/gininsert.c
+++ b/src/backend/access/gin/gininsert.c
@@ -51,7 +51,7 @@ addItemPointersToLeafTuple(GinState *ginstate,
 						   ItemPointerData *items, uint32 nitem,
 						   GinStatsData *buildStats, Buffer buffer)
 {
-	OffsetNumber attnum;
+	OffsetNumber attphysnum;
 	Datum		key;
 	GinNullCategory category;
 	IndexTuple	res;
@@ -63,11 +63,11 @@ addItemPointersToLeafTuple(GinState *ginstate,
 
 	Assert(!GinIsPostingTree(old));
 
-	attnum = gintuple_get_attrnum(ginstate, old);
+	attphysnum = gintuple_get_attrnum(ginstate, old);
 	key = gintuple_get_key(ginstate, old, &category);
 
 	/* merge the old and new posting lists */
-	oldItems = ginReadTuple(ginstate, attnum, old, &oldNPosting);
+	oldItems = ginReadTuple(ginstate, attphysnum, old, &oldNPosting);
 
 	newItems = ginMergeItemPointers(items, nitem,
 									oldItems, oldNPosting,
@@ -80,7 +80,7 @@ addItemPointersToLeafTuple(GinState *ginstate,
 	pfree(newItems);
 	if (compressedList)
 	{
-		res = GinFormTuple(ginstate, attnum, key, category,
+		res = GinFormTuple(ginstate, attphysnum, key, category,
 						   (char *) compressedList,
 						   SizeOfGinPostingList(compressedList),
 						   newNPosting,
@@ -109,7 +109,7 @@ addItemPointersToLeafTuple(GinState *ginstate,
 							  buildStats);
 
 		/* And build a new posting-tree-only result tuple */
-		res = GinFormTuple(ginstate, attnum, key, category, NULL, 0, 0, true);
+		res = GinFormTuple(ginstate, attphysnum, key, category, NULL, 0, 0, true);
 		GinSetPostingTree(res, postingRoot);
 	}
 	pfree(oldItems);
@@ -127,7 +127,7 @@ addItemPointersToLeafTuple(GinState *ginstate,
  */
 static IndexTuple
 buildFreshLeafTuple(GinState *ginstate,
-					OffsetNumber attnum, Datum key, GinNullCategory category,
+					OffsetNumber attphysnum, Datum key, GinNullCategory category,
 					ItemPointerData *items, uint32 nitem,
 					GinStatsData *buildStats, Buffer buffer)
 {
@@ -138,7 +138,7 @@ buildFreshLeafTuple(GinState *ginstate,
 	compressedList = ginCompressPostingList(items, nitem, GinMaxItemSize, NULL);
 	if (compressedList)
 	{
-		res = GinFormTuple(ginstate, attnum, key, category,
+		res = GinFormTuple(ginstate, attphysnum, key, category,
 						   (char *) compressedList,
 						   SizeOfGinPostingList(compressedList),
 						   nitem, false);
@@ -153,7 +153,7 @@ buildFreshLeafTuple(GinState *ginstate,
 		 * Build posting-tree-only result tuple.  We do this first so as to
 		 * fail quickly if the key is too big.
 		 */
-		res = GinFormTuple(ginstate, attnum, key, category, NULL, 0, 0, true);
+		res = GinFormTuple(ginstate, attphysnum, key, category, NULL, 0, 0, true);
 
 		/*
 		 * Initialize a new posting tree with the TIDs.
@@ -177,7 +177,7 @@ buildFreshLeafTuple(GinState *ginstate,
  */
 void
 ginEntryInsert(GinState *ginstate,
-			   OffsetNumber attnum, Datum key, GinNullCategory category,
+			   OffsetNumber attphysnum, Datum key, GinNullCategory category,
 			   ItemPointerData *items, uint32 nitem,
 			   GinStatsData *buildStats)
 {
@@ -189,7 +189,7 @@ ginEntryInsert(GinState *ginstate,
 
 	insertdata.isDelete = false;
 
-	ginPrepareEntryScan(&btree, attnum, key, category, ginstate);
+	ginPrepareEntryScan(&btree, attphysnum, key, category, ginstate);
 	btree.isBuild = (buildStats != NULL);
 
 	stack = ginFindLeafPage(&btree, false, false, NULL);
@@ -229,7 +229,7 @@ ginEntryInsert(GinState *ginstate,
 		CheckForSerializableConflictIn(ginstate->index, NULL,
 									   BufferGetBlockNumber(stack->buffer));
 		/* no match, so construct a new leaf entry */
-		itup = buildFreshLeafTuple(ginstate, attnum, key, category,
+		itup = buildFreshLeafTuple(ginstate, attphysnum, key, category,
 								   items, nitem, buildStats, stack->buffer);
 
 		/*
@@ -253,7 +253,7 @@ ginEntryInsert(GinState *ginstate,
  * This function is used only during initial index creation.
  */
 static void
-ginHeapTupleBulkInsert(GinBuildState *buildstate, OffsetNumber attnum,
+ginHeapTupleBulkInsert(GinBuildState *buildstate, OffsetNumber attphysnum,
 					   Datum value, bool isNull,
 					   ItemPointer heapptr)
 {
@@ -263,12 +263,12 @@ ginHeapTupleBulkInsert(GinBuildState *buildstate, OffsetNumber attnum,
 	MemoryContext oldCtx;
 
 	oldCtx = MemoryContextSwitchTo(buildstate->funcCtx);
-	entries = ginExtractEntries(buildstate->accum.ginstate, attnum,
+	entries = ginExtractEntries(buildstate->accum.ginstate, attphysnum,
 								value, isNull,
 								&nentries, &categories);
 	MemoryContextSwitchTo(oldCtx);
 
-	ginInsertBAEntries(&buildstate->accum, heapptr, attnum,
+	ginInsertBAEntries(&buildstate->accum, heapptr, attphysnum,
 					   entries, categories, nentries);
 
 	buildstate->indtuples += nentries;
@@ -297,15 +297,15 @@ ginBuildCallback(Relation index, ItemPointer tid, Datum *values,
 		Datum		key;
 		GinNullCategory category;
 		uint32		nlist;
-		OffsetNumber attnum;
+		OffsetNumber attphysnum;
 
 		ginBeginBAScan(&buildstate->accum);
 		while ((list = ginGetBAEntry(&buildstate->accum,
-									 &attnum, &key, &category, &nlist)) != NULL)
+									 &attphysnum, &key, &category, &nlist)) != NULL)
 		{
 			/* there could be many entries, so be willing to abort here */
 			CHECK_FOR_INTERRUPTS();
-			ginEntryInsert(&buildstate->ginstate, attnum, key, category,
+			ginEntryInsert(&buildstate->ginstate, attphysnum, key, category,
 						   list, nlist, &buildstate->buildStats);
 		}
 
@@ -329,7 +329,7 @@ ginbuild(Relation heap, Relation index, IndexInfo *indexInfo)
 	GinNullCategory category;
 	uint32		nlist;
 	MemoryContext oldCtx;
-	OffsetNumber attnum;
+	OffsetNumber attphysnum;
 
 	if (RelationGetNumberOfBlocks(index) != 0)
 		elog(ERROR, "index \"%s\" already contains data",
@@ -390,11 +390,11 @@ ginbuild(Relation heap, Relation index, IndexInfo *indexInfo)
 	oldCtx = MemoryContextSwitchTo(buildstate.tmpCtx);
 	ginBeginBAScan(&buildstate.accum);
 	while ((list = ginGetBAEntry(&buildstate.accum,
-								 &attnum, &key, &category, &nlist)) != NULL)
+								 &attphysnum, &key, &category, &nlist)) != NULL)
 	{
 		/* there could be many entries, so be willing to abort here */
 		CHECK_FOR_INTERRUPTS();
-		ginEntryInsert(&buildstate.ginstate, attnum, key, category,
+		ginEntryInsert(&buildstate.ginstate, attphysnum, key, category,
 					   list, nlist, &buildstate.buildStats);
 	}
 	MemoryContextSwitchTo(oldCtx);
@@ -467,7 +467,7 @@ ginbuildempty(Relation index)
  * (non-fast-update) insertion
  */
 static void
-ginHeapTupleInsert(GinState *ginstate, OffsetNumber attnum,
+ginHeapTupleInsert(GinState *ginstate, OffsetNumber attphysnum,
 				   Datum value, bool isNull,
 				   ItemPointer item)
 {
@@ -476,11 +476,11 @@ ginHeapTupleInsert(GinState *ginstate, OffsetNumber attnum,
 	int32		i,
 				nentries;
 
-	entries = ginExtractEntries(ginstate, attnum, value, isNull,
+	entries = ginExtractEntries(ginstate, attphysnum, value, isNull,
 								&nentries, &categories);
 
 	for (i = 0; i < nentries; i++)
-		ginEntryInsert(ginstate, attnum, entries[i], categories[i],
+		ginEntryInsert(ginstate, attphysnum, entries[i], categories[i],
 					   item, 1, NULL);
 }
 
diff --git a/src/backend/access/gin/ginlogic.c b/src/backend/access/gin/ginlogic.c
index c38c27fbae..442c338631 100644
--- a/src/backend/access/gin/ginlogic.c
+++ b/src/backend/access/gin/ginlogic.c
@@ -229,16 +229,16 @@ ginInitConsistentFunction(GinState *ginstate, GinScanKey key)
 	}
 	else
 	{
-		key->consistentFmgrInfo = &ginstate->consistentFn[key->attnum - 1];
-		key->triConsistentFmgrInfo = &ginstate->triConsistentFn[key->attnum - 1];
-		key->collation = ginstate->supportCollation[key->attnum - 1];
+		key->consistentFmgrInfo = &ginstate->consistentFn[key->attphysnum - 1];
+		key->triConsistentFmgrInfo = &ginstate->triConsistentFn[key->attphysnum - 1];
+		key->collation = ginstate->supportCollation[key->attphysnum - 1];
 
-		if (OidIsValid(ginstate->consistentFn[key->attnum - 1].fn_oid))
+		if (OidIsValid(ginstate->consistentFn[key->attphysnum - 1].fn_oid))
 			key->boolConsistentFn = directBoolConsistentFn;
 		else
 			key->boolConsistentFn = shimBoolConsistentFn;
 
-		if (OidIsValid(ginstate->triConsistentFn[key->attnum - 1].fn_oid))
+		if (OidIsValid(ginstate->triConsistentFn[key->attphysnum - 1].fn_oid))
 			key->triConsistentFn = directTriConsistentFn;
 		else
 			key->triConsistentFn = shimTriConsistentFn;
diff --git a/src/backend/access/gin/ginscan.c b/src/backend/access/gin/ginscan.c
index b776d04459..8bf5cfe7f7 100644
--- a/src/backend/access/gin/ginscan.c
+++ b/src/backend/access/gin/ginscan.c
@@ -54,7 +54,7 @@ ginbeginscan(Relation rel, int nkeys, int norderbys)
  * in which case just return it
  */
 static GinScanEntry
-ginFillScanEntry(GinScanOpaque so, OffsetNumber attnum,
+ginFillScanEntry(GinScanOpaque so, OffsetNumber attphysnum,
 				 StrategyNumber strategy, int32 searchMode,
 				 Datum queryKey, GinNullCategory queryCategory,
 				 bool isPartialMatch, Pointer extra_data)
@@ -79,8 +79,8 @@ ginFillScanEntry(GinScanOpaque so, OffsetNumber attnum,
 				prevEntry->isPartialMatch == isPartialMatch &&
 				prevEntry->strategy == strategy &&
 				prevEntry->searchMode == searchMode &&
-				prevEntry->attnum == attnum &&
-				ginCompareEntries(ginstate, attnum,
+				prevEntry->attphysnum == attphysnum &&
+				ginCompareEntries(ginstate, attphysnum,
 								  prevEntry->queryKey,
 								  prevEntry->queryCategory,
 								  queryKey,
@@ -100,7 +100,7 @@ ginFillScanEntry(GinScanOpaque so, OffsetNumber attnum,
 	scanEntry->extra_data = extra_data;
 	scanEntry->strategy = strategy;
 	scanEntry->searchMode = searchMode;
-	scanEntry->attnum = attnum;
+	scanEntry->attphysnum = attphysnum;
 
 	scanEntry->buffer = InvalidBuffer;
 	ItemPointerSetMin(&scanEntry->curItem);
@@ -140,7 +140,7 @@ ginScanKeyAddHiddenEntry(GinScanOpaque so, GinScanKey key,
 	int			i = key->nentries++;
 
 	/* strategy is of no interest because this is not a partial-match item */
-	key->scanEntry[i] = ginFillScanEntry(so, key->attnum,
+	key->scanEntry[i] = ginFillScanEntry(so, key->attphysnum,
 										 InvalidStrategy, key->searchMode,
 										 (Datum) 0, queryCategory,
 										 false, NULL);
@@ -150,7 +150,7 @@ ginScanKeyAddHiddenEntry(GinScanOpaque so, GinScanKey key,
  * Initialize the next GinScanKey using the output from the extractQueryFn
  */
 static void
-ginFillScanKey(GinScanOpaque so, OffsetNumber attnum,
+ginFillScanKey(GinScanOpaque so, OffsetNumber attphysnum,
 			   StrategyNumber strategy, int32 searchMode,
 			   Datum query, uint32 nQueryValues,
 			   Datum *queryValues, GinNullCategory *queryCategories,
@@ -175,7 +175,7 @@ ginFillScanKey(GinScanOpaque so, OffsetNumber attnum,
 	key->extra_data = extra_data;
 	key->strategy = strategy;
 	key->searchMode = searchMode;
-	key->attnum = attnum;
+	key->attphysnum = attphysnum;
 
 	/*
 	 * Initially, scan keys of GIN_SEARCH_MODE_ALL mode are marked
@@ -205,11 +205,11 @@ ginFillScanKey(GinScanOpaque so, OffsetNumber attnum,
 		queryKey = queryValues[i];
 		queryCategory = queryCategories[i];
 		isPartialMatch =
-			(ginstate->canPartialMatch[attnum - 1] && partial_matches)
+			(ginstate->canPartialMatch[attphysnum - 1] && partial_matches)
 			? partial_matches[i] : false;
 		this_extra = (extra_data) ? extra_data[i] : NULL;
 
-		key->scanEntry[i] = ginFillScanEntry(so, attnum,
+		key->scanEntry[i] = ginFillScanEntry(so, attphysnum,
 											 strategy, searchMode,
 											 queryKey, queryCategory,
 											 isPartialMatch, this_extra);
@@ -394,11 +394,11 @@ ginNewScanKey(IndexScanDesc scan)
 		if (key->searchMode != GIN_SEARCH_MODE_ALL)
 			continue;
 
-		if (!attrHasNormalScan[key->attnum - 1])
+		if (!attrHasNormalScan[key->attphysnum - 1])
 		{
 			key->excludeOnly = false;
 			ginScanKeyAddHiddenEntry(so, key, GIN_CAT_EMPTY_QUERY);
-			attrHasNormalScan[key->attnum - 1] = true;
+			attrHasNormalScan[key->attphysnum - 1] = true;
 		}
 	}
 
diff --git a/src/backend/access/gin/ginutil.c b/src/backend/access/gin/ginutil.c
index 20f470648b..caca0c4de4 100644
--- a/src/backend/access/gin/ginutil.c
+++ b/src/backend/access/gin/ginutil.c
@@ -391,7 +391,7 @@ GinInitMetabuffer(Buffer b)
  * Compare two keys of the same index column
  */
 int
-ginCompareEntries(GinState *ginstate, OffsetNumber attnum,
+ginCompareEntries(GinState *ginstate, OffsetNumber attphysnum,
 				  Datum a, GinNullCategory categorya,
 				  Datum b, GinNullCategory categoryb)
 {
@@ -404,8 +404,8 @@ ginCompareEntries(GinState *ginstate, OffsetNumber attnum,
 		return 0;
 
 	/* both not null, so safe to call the compareFn */
-	return DatumGetInt32(FunctionCall2Coll(&ginstate->compareFn[attnum - 1],
-										   ginstate->supportCollation[attnum - 1],
+	return DatumGetInt32(FunctionCall2Coll(&ginstate->compareFn[attphysnum - 1],
+										   ginstate->supportCollation[attphysnum - 1],
 										   a, b));
 }
 
@@ -486,7 +486,7 @@ cmpEntries(const void *a, const void *b, void *arg)
  * This avoids generating redundant index entries.
  */
 Datum *
-ginExtractEntries(GinState *ginstate, OffsetNumber attnum,
+ginExtractEntries(GinState *ginstate, OffsetNumber attphysnum,
 				  Datum value, bool isNull,
 				  int32 *nentries, GinNullCategory **categories)
 {
@@ -511,8 +511,8 @@ ginExtractEntries(GinState *ginstate, OffsetNumber attnum,
 	/* OK, call the opclass's extractValueFn */
 	nullFlags = NULL;			/* in case extractValue doesn't set it */
 	entries = (Datum *)
-		DatumGetPointer(FunctionCall3Coll(&ginstate->extractValueFn[attnum - 1],
-										  ginstate->supportCollation[attnum - 1],
+		DatumGetPointer(FunctionCall3Coll(&ginstate->extractValueFn[attphysnum - 1],
+										  ginstate->supportCollation[attphysnum - 1],
 										  value,
 										  PointerGetDatum(nentries),
 										  PointerGetDatum(&nullFlags)));
@@ -556,8 +556,8 @@ ginExtractEntries(GinState *ginstate, OffsetNumber attnum,
 			keydata[i].isnull = nullFlags[i];
 		}
 
-		arg.cmpDatumFunc = &ginstate->compareFn[attnum - 1];
-		arg.collation = ginstate->supportCollation[attnum - 1];
+		arg.cmpDatumFunc = &ginstate->compareFn[attphysnum - 1];
+		arg.collation = ginstate->supportCollation[attphysnum - 1];
 		arg.haveDups = false;
 		qsort_arg(keydata, *nentries, sizeof(keyEntryData),
 				  cmpEntries, (void *) &arg);
diff --git a/src/backend/access/gin/ginvacuum.c b/src/backend/access/gin/ginvacuum.c
index b4fa5f6bf8..67293adee3 100644
--- a/src/backend/access/gin/ginvacuum.c
+++ b/src/backend/access/gin/ginvacuum.c
@@ -506,7 +506,7 @@ ginVacuumEntryPage(GinVacuumState *gvs, Buffer buffer, BlockNumber *roots, uint3
 			/* If any item pointers were removed, recreate the tuple. */
 			if (items)
 			{
-				OffsetNumber attnum;
+				OffsetNumber attphysnum;
 				Datum		key;
 				GinNullCategory category;
 				GinPostingList *plist;
@@ -539,9 +539,9 @@ ginVacuumEntryPage(GinVacuumState *gvs, Buffer buffer, BlockNumber *roots, uint3
 					itup = (IndexTuple) PageGetItem(tmppage, PageGetItemId(tmppage, i));
 				}
 
-				attnum = gintuple_get_attrnum(&gvs->ginstate, itup);
+				attphysnum = gintuple_get_attrnum(&gvs->ginstate, itup);
 				key = gintuple_get_key(&gvs->ginstate, itup, &category);
-				itup = GinFormTuple(&gvs->ginstate, attnum, key, category,
+				itup = GinFormTuple(&gvs->ginstate, attphysnum, key, category,
 									(char *) plist, plistsize,
 									nitems, true);
 				if (plist)
diff --git a/src/backend/access/index/genam.c b/src/backend/access/index/genam.c
index 98af5347b9..46cce23c46 100644
--- a/src/backend/access/index/genam.c
+++ b/src/backend/access/index/genam.c
@@ -216,16 +216,16 @@ BuildIndexValueDescription(Relation indexRelation,
 		 */
 		for (keyno = 0; keyno < indnkeyatts; keyno++)
 		{
-			AttrNumber	attnum = idxrec->indkey.values[keyno];
+			AttrNumber	attphysnum = idxrec->indkey.values[keyno];
 
 			/*
-			 * Note that if attnum == InvalidAttrNumber, then this is an index
+			 * Note that if attphysnum == InvalidAttrNumber, then this is an index
 			 * based on an expression and we return no detail rather than try
 			 * to figure out what column(s) the expression includes and if the
 			 * user has SELECT rights on them.
 			 */
-			if (attnum == InvalidAttrNumber ||
-				pg_attribute_aclcheck(indrelid, attnum, GetUserId(),
+			if (attphysnum == InvalidAttrNumber ||
+				pg_attribute_aclcheck(indrelid, attphysnum, GetUserId(),
 									  ACL_SELECT) != ACLCHECK_OK)
 			{
 				/* No access, so clean up and return */
diff --git a/src/backend/access/index/indexam.c b/src/backend/access/index/indexam.c
index fe80b8b0ba..e6e8ddafea 100644
--- a/src/backend/access/index/indexam.c
+++ b/src/backend/access/index/indexam.c
@@ -767,7 +767,7 @@ index_can_return(Relation indexRelation, int attno)
  */
 RegProcedure
 index_getprocid(Relation irel,
-				AttrNumber attnum,
+				AttrNumber attphysnum,
 				uint16 procnum)
 {
 	RegProcedure *loc;
@@ -778,7 +778,7 @@ index_getprocid(Relation irel,
 
 	Assert(procnum > 0 && procnum <= (uint16) nproc);
 
-	procindex = (nproc * (attnum - 1)) + (procnum - 1);
+	procindex = (nproc * (attphysnum - 1)) + (procnum - 1);
 
 	loc = irel->rd_support;
 
@@ -801,7 +801,7 @@ index_getprocid(Relation irel,
  */
 FmgrInfo *
 index_getprocinfo(Relation irel,
-				  AttrNumber attnum,
+				  AttrNumber attphysnum,
 				  uint16 procnum)
 {
 	FmgrInfo   *locinfo;
@@ -814,7 +814,7 @@ index_getprocinfo(Relation irel,
 
 	Assert(procnum > 0 && procnum <= (uint16) nproc);
 
-	procindex = (nproc * (attnum - 1)) + (procnum - 1);
+	procindex = (nproc * (attphysnum - 1)) + (procnum - 1);
 
 	locinfo = irel->rd_supportinfo;
 
@@ -840,7 +840,7 @@ index_getprocinfo(Relation irel,
 		 */
 		if (!RegProcedureIsValid(procId))
 			elog(ERROR, "missing support function %d for attribute %d of index \"%s\"",
-				 procnum, attnum, RelationGetRelationName(irel));
+				 procnum, attphysnum, RelationGetRelationName(irel));
 
 		fmgr_info_cxt(procId, locinfo, irel->rd_indexcxt);
 
@@ -850,7 +850,7 @@ index_getprocinfo(Relation irel,
 			bytea	  **attoptions = RelationGetIndexAttOptions(irel, false);
 			MemoryContext oldcxt = MemoryContextSwitchTo(irel->rd_indexcxt);
 
-			set_fn_opclass_options(locinfo, attoptions[attnum - 1]);
+			set_fn_opclass_options(locinfo, attoptions[attphysnum - 1]);
 
 			MemoryContextSwitchTo(oldcxt);
 		}
@@ -936,7 +936,7 @@ index_store_float8_orderby_distances(IndexScanDesc scan, Oid *orderByTypes,
  * ----------------
  */
 bytea *
-index_opclass_options(Relation indrel, AttrNumber attnum, Datum attoptions,
+index_opclass_options(Relation indrel, AttrNumber attphysnum, Datum attoptions,
 					  bool validate)
 {
 	int			amoptsprocnum = indrel->rd_indam->amoptsprocnum;
@@ -946,7 +946,7 @@ index_opclass_options(Relation indrel, AttrNumber attnum, Datum attoptions,
 
 	/* fetch options support procedure if specified */
 	if (amoptsprocnum != 0)
-		procid = index_getprocid(indrel, attnum, amoptsprocnum);
+		procid = index_getprocid(indrel, attphysnum, amoptsprocnum);
 
 	if (!OidIsValid(procid))
 	{
@@ -966,7 +966,7 @@ index_opclass_options(Relation indrel, AttrNumber attnum, Datum attoptions,
 										Anum_pg_index_indclass, &isnull);
 		Assert(!isnull);
 		indclass = (oidvector *) DatumGetPointer(indclassDatum);
-		opclass = indclass->values[attnum - 1];
+		opclass = indclass->values[attphysnum - 1];
 
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -976,7 +976,7 @@ index_opclass_options(Relation indrel, AttrNumber attnum, Datum attoptions,
 
 	init_local_reloptions(&relopts, 0);
 
-	procinfo = index_getprocinfo(indrel, attnum, amoptsprocnum);
+	procinfo = index_getprocinfo(indrel, attphysnum, amoptsprocnum);
 
 	(void) FunctionCall1(procinfo, PointerGetDatum(&relopts));
 
diff --git a/src/backend/access/nbtree/nbtutils.c b/src/backend/access/nbtree/nbtutils.c
index ff260c393a..9c5f50f84f 100644
--- a/src/backend/access/nbtree/nbtutils.c
+++ b/src/backend/access/nbtree/nbtutils.c
@@ -2365,15 +2365,15 @@ _bt_keep_natts(Relation rel, IndexTuple lastleft, IndexTuple firstright,
 
 	scankey = itup_key->scankeys;
 	keepnatts = 1;
-	for (int attnum = 1; attnum <= nkeyatts; attnum++, scankey++)
+	for (int attphysnum = 1; attphysnum <= nkeyatts; attphysnum++, scankey++)
 	{
 		Datum		datum1,
 					datum2;
 		bool		isNull1,
 					isNull2;
 
-		datum1 = index_getattr(lastleft, attnum, itupdesc, &isNull1);
-		datum2 = index_getattr(firstright, attnum, itupdesc, &isNull2);
+		datum1 = index_getattr(lastleft, attphysnum, itupdesc, &isNull1);
+		datum2 = index_getattr(firstright, attphysnum, itupdesc, &isNull2);
 
 		if (isNull1 != isNull2)
 			break;
@@ -2428,7 +2428,7 @@ _bt_keep_natts_fast(Relation rel, IndexTuple lastleft, IndexTuple firstright)
 	int			keepnatts;
 
 	keepnatts = 1;
-	for (int attnum = 1; attnum <= keysz; attnum++)
+	for (int attphysnum = 1; attphysnum <= keysz; attphysnum++)
 	{
 		Datum		datum1,
 					datum2;
@@ -2436,9 +2436,9 @@ _bt_keep_natts_fast(Relation rel, IndexTuple lastleft, IndexTuple firstright)
 					isNull2;
 		Form_pg_attribute att;
 
-		datum1 = index_getattr(lastleft, attnum, itupdesc, &isNull1);
-		datum2 = index_getattr(firstright, attnum, itupdesc, &isNull2);
-		att = TupleDescAttr(itupdesc, attnum - 1);
+		datum1 = index_getattr(lastleft, attphysnum, itupdesc, &isNull1);
+		datum2 = index_getattr(firstright, attphysnum, itupdesc, &isNull2);
+		att = TupleDescAttr(itupdesc, attphysnum - 1);
 
 		if (isNull1 != isNull2)
 			break;
diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index 9a610d41ad..37107dc12b 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -453,7 +453,7 @@ boot_openrel(char *relname)
 			Form_pg_attribute at = attrtypes[i];
 
 			elog(DEBUG4, "create attribute %d name %s len %d num %d type %u",
-				 i, NameStr(at->attname), at->attlen, at->attnum,
+				 i, NameStr(at->attname), at->attlen, at->attphysnum,
 				 at->atttypid);
 		}
 	}
@@ -501,7 +501,7 @@ closerel(char *name)
  * ----------------
  */
 void
-DefineAttr(char *name, char *type, int attnum, int nullness)
+DefineAttr(char *name, char *type, int attphysnum, int nullness)
 {
 	Oid			typeoid;
 
@@ -511,46 +511,46 @@ DefineAttr(char *name, char *type, int attnum, int nullness)
 		closerel(NULL);
 	}
 
-	if (attrtypes[attnum] == NULL)
-		attrtypes[attnum] = AllocateAttribute();
-	MemSet(attrtypes[attnum], 0, ATTRIBUTE_FIXED_PART_SIZE);
+	if (attrtypes[attphysnum] == NULL)
+		attrtypes[attphysnum] = AllocateAttribute();
+	MemSet(attrtypes[attphysnum], 0, ATTRIBUTE_FIXED_PART_SIZE);
 
-	namestrcpy(&attrtypes[attnum]->attname, name);
-	elog(DEBUG4, "column %s %s", NameStr(attrtypes[attnum]->attname), type);
-	attrtypes[attnum]->attnum = attnum + 1;
+	namestrcpy(&attrtypes[attphysnum]->attname, name);
+	elog(DEBUG4, "column %s %s", NameStr(attrtypes[attphysnum]->attname), type);
+	attrtypes[attphysnum]->attphysnum = attphysnum + 1;
 
 	typeoid = gettype(type);
 
 	if (Typ != NIL)
 	{
-		attrtypes[attnum]->atttypid = Ap->am_oid;
-		attrtypes[attnum]->attlen = Ap->am_typ.typlen;
-		attrtypes[attnum]->attbyval = Ap->am_typ.typbyval;
-		attrtypes[attnum]->attalign = Ap->am_typ.typalign;
-		attrtypes[attnum]->attstorage = Ap->am_typ.typstorage;
-		attrtypes[attnum]->attcompression = InvalidCompressionMethod;
-		attrtypes[attnum]->attcollation = Ap->am_typ.typcollation;
+		attrtypes[attphysnum]->atttypid = Ap->am_oid;
+		attrtypes[attphysnum]->attlen = Ap->am_typ.typlen;
+		attrtypes[attphysnum]->attbyval = Ap->am_typ.typbyval;
+		attrtypes[attphysnum]->attalign = Ap->am_typ.typalign;
+		attrtypes[attphysnum]->attstorage = Ap->am_typ.typstorage;
+		attrtypes[attphysnum]->attcompression = InvalidCompressionMethod;
+		attrtypes[attphysnum]->attcollation = Ap->am_typ.typcollation;
 		/* if an array type, assume 1-dimensional attribute */
 		if (Ap->am_typ.typelem != InvalidOid && Ap->am_typ.typlen < 0)
-			attrtypes[attnum]->attndims = 1;
+			attrtypes[attphysnum]->attndims = 1;
 		else
-			attrtypes[attnum]->attndims = 0;
+			attrtypes[attphysnum]->attndims = 0;
 	}
 	else
 	{
-		attrtypes[attnum]->atttypid = TypInfo[typeoid].oid;
-		attrtypes[attnum]->attlen = TypInfo[typeoid].len;
-		attrtypes[attnum]->attbyval = TypInfo[typeoid].byval;
-		attrtypes[attnum]->attalign = TypInfo[typeoid].align;
-		attrtypes[attnum]->attstorage = TypInfo[typeoid].storage;
-		attrtypes[attnum]->attcompression = InvalidCompressionMethod;
-		attrtypes[attnum]->attcollation = TypInfo[typeoid].collation;
+		attrtypes[attphysnum]->atttypid = TypInfo[typeoid].oid;
+		attrtypes[attphysnum]->attlen = TypInfo[typeoid].len;
+		attrtypes[attphysnum]->attbyval = TypInfo[typeoid].byval;
+		attrtypes[attphysnum]->attalign = TypInfo[typeoid].align;
+		attrtypes[attphysnum]->attstorage = TypInfo[typeoid].storage;
+		attrtypes[attphysnum]->attcompression = InvalidCompressionMethod;
+		attrtypes[attphysnum]->attcollation = TypInfo[typeoid].collation;
 		/* if an array type, assume 1-dimensional attribute */
 		if (TypInfo[typeoid].elem != InvalidOid &&
-			attrtypes[attnum]->attlen < 0)
-			attrtypes[attnum]->attndims = 1;
+			attrtypes[attphysnum]->attlen < 0)
+			attrtypes[attphysnum]->attndims = 1;
 		else
-			attrtypes[attnum]->attndims = 0;
+			attrtypes[attphysnum]->attndims = 0;
 	}
 
 	/*
@@ -559,21 +559,21 @@ DefineAttr(char *name, char *type, int attnum, int nullness)
 	 * collation.  This is essential to allow template0 to be cloned with a
 	 * different database collation.
 	 */
-	if (OidIsValid(attrtypes[attnum]->attcollation))
-		attrtypes[attnum]->attcollation = C_COLLATION_OID;
+	if (OidIsValid(attrtypes[attphysnum]->attcollation))
+		attrtypes[attphysnum]->attcollation = C_COLLATION_OID;
 
-	attrtypes[attnum]->attstattarget = -1;
-	attrtypes[attnum]->attcacheoff = -1;
-	attrtypes[attnum]->atttypmod = -1;
-	attrtypes[attnum]->attislocal = true;
+	attrtypes[attphysnum]->attstattarget = -1;
+	attrtypes[attphysnum]->attcacheoff = -1;
+	attrtypes[attphysnum]->atttypmod = -1;
+	attrtypes[attphysnum]->attislocal = true;
 
 	if (nullness == BOOTCOL_NULL_FORCE_NOT_NULL)
 	{
-		attrtypes[attnum]->attnotnull = true;
+		attrtypes[attphysnum]->attnotnull = true;
 	}
 	else if (nullness == BOOTCOL_NULL_FORCE_NULL)
 	{
-		attrtypes[attnum]->attnotnull = false;
+		attrtypes[attphysnum]->attnotnull = false;
 	}
 	else
 	{
@@ -584,19 +584,19 @@ DefineAttr(char *name, char *type, int attnum, int nullness)
 		 * likewise fixed-width and not-null.  This corresponds to case where
 		 * column can be accessed directly via C struct declaration.
 		 */
-		if (attrtypes[attnum]->attlen > 0)
+		if (attrtypes[attphysnum]->attlen > 0)
 		{
 			int			i;
 
 			/* check earlier attributes */
-			for (i = 0; i < attnum; i++)
+			for (i = 0; i < attphysnum; i++)
 			{
 				if (attrtypes[i]->attlen <= 0 ||
 					!attrtypes[i]->attnotnull)
 					break;
 			}
-			if (i == attnum)
-				attrtypes[attnum]->attnotnull = true;
+			if (i == attphysnum)
+				attrtypes[attphysnum]->attnotnull = true;
 		}
 	}
 }
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index 5f1726c095..3f5cbebcbc 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -137,7 +137,7 @@ static AclMode restrict_and_check_grant(bool is_grant, AclMode avail_goptions,
 										Oid objectId, Oid grantorId,
 										ObjectType objtype, const char *objname,
 										AttrNumber att_number, const char *colname);
-static AclMode pg_aclmask(ObjectType objtype, Oid table_oid, AttrNumber attnum,
+static AclMode pg_aclmask(ObjectType objtype, Oid table_oid, AttrNumber attphysnum,
 						  Oid roleid, AclMode mask, AclMaskHow how);
 static void recordExtensionInitPriv(Oid objoid, Oid classoid, int objsubid,
 									Acl *new_acl);
@@ -1578,18 +1578,18 @@ expand_col_privileges(List *colnames, Oid table_oid,
 	foreach(cell, colnames)
 	{
 		char	   *colname = strVal(lfirst(cell));
-		AttrNumber	attnum;
+		AttrNumber	attphysnum;
 
-		attnum = get_attnum(table_oid, colname);
-		if (attnum == InvalidAttrNumber)
+		attphysnum = get_attphysnum(table_oid, colname);
+		if (attphysnum == InvalidAttrNumber)
 			ereport(ERROR,
 					(errcode(ERRCODE_UNDEFINED_COLUMN),
 					 errmsg("column \"%s\" of relation \"%s\" does not exist",
 							colname, get_rel_name(table_oid))));
-		attnum -= FirstLowInvalidHeapAttributeNumber;
-		if (attnum <= 0 || attnum >= num_col_privileges)
+		attphysnum -= FirstLowInvalidHeapAttributeNumber;
+		if (attphysnum <= 0 || attphysnum >= num_col_privileges)
 			elog(ERROR, "column number out of range");	/* safety check */
-		col_privileges[attnum] |= this_privileges;
+		col_privileges[attphysnum] |= this_privileges;
 	}
 }
 
@@ -1623,7 +1623,7 @@ expand_all_col_privileges(Oid table_oid, Form_pg_class classForm,
 		if (classForm->relkind == RELKIND_VIEW && curr_att < 0)
 			continue;
 
-		attTuple = SearchSysCache2(ATTNUM,
+		attTuple = SearchSysCache2(ATTPHYSNUM,
 								   ObjectIdGetDatum(table_oid),
 								   Int16GetDatum(curr_att));
 		if (!HeapTupleIsValid(attTuple))
@@ -1648,7 +1648,7 @@ expand_all_col_privileges(Oid table_oid, Form_pg_class classForm,
  */
 static void
 ExecGrant_Attribute(InternalGrant *istmt, Oid relOid, const char *relname,
-					AttrNumber attnum, Oid ownerId, AclMode col_privileges,
+					AttrNumber attphysnum, Oid ownerId, AclMode col_privileges,
 					Relation attRelation, const Acl *old_rel_acl)
 {
 	HeapTuple	attr_tuple;
@@ -1670,20 +1670,20 @@ ExecGrant_Attribute(InternalGrant *istmt, Oid relOid, const char *relname,
 	Oid		   *oldmembers;
 	Oid		   *newmembers;
 
-	attr_tuple = SearchSysCache2(ATTNUM,
+	attr_tuple = SearchSysCache2(ATTPHYSNUM,
 								 ObjectIdGetDatum(relOid),
-								 Int16GetDatum(attnum));
+								 Int16GetDatum(attphysnum));
 	if (!HeapTupleIsValid(attr_tuple))
 		elog(ERROR, "cache lookup failed for attribute %d of relation %u",
-			 attnum, relOid);
+			 attphysnum, relOid);
 	pg_attribute_tuple = (Form_pg_attribute) GETSTRUCT(attr_tuple);
 
 	/*
 	 * Get working copy of existing ACL. If there's no ACL, substitute the
 	 * proper default.
 	 */
-	aclDatum = SysCacheGetAttr(ATTNUM, attr_tuple, Anum_pg_attribute_attacl,
-							   &isNull);
+	aclDatum = SysCacheGetAttr(ATTPHYSNUM, attr_tuple,
+							   Anum_pg_attribute_attacl, &isNull);
 	if (isNull)
 	{
 		old_acl = acldefault(OBJECT_COLUMN, ownerId);
@@ -1726,7 +1726,7 @@ ExecGrant_Attribute(InternalGrant *istmt, Oid relOid, const char *relname,
 								 (col_privileges == ACL_ALL_RIGHTS_COLUMN),
 								 col_privileges,
 								 relOid, grantorId, OBJECT_COLUMN,
-								 relname, attnum,
+								 relname, attphysnum,
 								 NameStr(pg_attribute_tuple->attname));
 
 	/*
@@ -1776,11 +1776,11 @@ ExecGrant_Attribute(InternalGrant *istmt, Oid relOid, const char *relname,
 		CatalogTupleUpdate(attRelation, &newtuple->t_self, newtuple);
 
 		/* Update initial privileges for extensions */
-		recordExtensionInitPriv(relOid, RelationRelationId, attnum,
+		recordExtensionInitPriv(relOid, RelationRelationId, attphysnum,
 								ACL_NUM(new_acl) > 0 ? new_acl : NULL);
 
 		/* Update the shared dependency ACL info */
-		updateAclDependencies(RelationRelationId, relOid, attnum,
+		updateAclDependencies(RelationRelationId, relOid, attphysnum,
 							  ownerId,
 							  noldmembers, oldmembers,
 							  nnewmembers, newmembers);
@@ -3840,7 +3840,7 @@ aclcheck_error_type(AclResult aclerr, Oid typeOid)
  * Relay for the various pg_*_mask routines depending on object kind
  */
 static AclMode
-pg_aclmask(ObjectType objtype, Oid table_oid, AttrNumber attnum, Oid roleid,
+pg_aclmask(ObjectType objtype, Oid table_oid, AttrNumber attphysnum, Oid roleid,
 		   AclMode mask, AclMaskHow how)
 {
 	switch (objtype)
@@ -3848,7 +3848,7 @@ pg_aclmask(ObjectType objtype, Oid table_oid, AttrNumber attnum, Oid roleid,
 		case OBJECT_COLUMN:
 			return
 				pg_class_aclmask(table_oid, roleid, mask, how) |
-				pg_attribute_aclmask(table_oid, attnum, roleid, mask, how);
+				pg_attribute_aclmask(table_oid, attphysnum, roleid, mask, how);
 		case OBJECT_TABLE:
 		case OBJECT_SEQUENCE:
 			return pg_class_aclmask(table_oid, roleid, mask, how);
@@ -3910,10 +3910,10 @@ pg_aclmask(ObjectType objtype, Oid table_oid, AttrNumber attnum, Oid roleid,
  * superuser-ness here.)
  */
 AclMode
-pg_attribute_aclmask(Oid table_oid, AttrNumber attnum, Oid roleid,
+pg_attribute_aclmask(Oid table_oid, AttrNumber attphysnum, Oid roleid,
 					 AclMode mask, AclMaskHow how)
 {
-	return pg_attribute_aclmask_ext(table_oid, attnum, roleid,
+	return pg_attribute_aclmask_ext(table_oid, attphysnum, roleid,
 									mask, how, NULL);
 }
 
@@ -3924,7 +3924,7 @@ pg_attribute_aclmask(Oid table_oid, AttrNumber attnum, Oid roleid,
  * callers to avoid the missing attribute ERROR when is_missing is non-NULL.
  */
 AclMode
-pg_attribute_aclmask_ext(Oid table_oid, AttrNumber attnum, Oid roleid,
+pg_attribute_aclmask_ext(Oid table_oid, AttrNumber attphysnum, Oid roleid,
 						 AclMode mask, AclMaskHow how, bool *is_missing)
 {
 	AclMode		result;
@@ -3940,9 +3940,9 @@ pg_attribute_aclmask_ext(Oid table_oid, AttrNumber attnum, Oid roleid,
 	/*
 	 * First, get the column's ACL from its pg_attribute entry
 	 */
-	attTuple = SearchSysCache2(ATTNUM,
+	attTuple = SearchSysCache2(ATTPHYSNUM,
 							   ObjectIdGetDatum(table_oid),
-							   Int16GetDatum(attnum));
+							   Int16GetDatum(attphysnum));
 	if (!HeapTupleIsValid(attTuple))
 	{
 		if (is_missing != NULL)
@@ -3955,7 +3955,7 @@ pg_attribute_aclmask_ext(Oid table_oid, AttrNumber attnum, Oid roleid,
 			ereport(ERROR,
 					(errcode(ERRCODE_UNDEFINED_COLUMN),
 					 errmsg("attribute %d of relation with OID %u does not exist",
-							attnum, table_oid)));
+							attphysnum, table_oid)));
 	}
 
 	attributeForm = (Form_pg_attribute) GETSTRUCT(attTuple);
@@ -3974,10 +3974,10 @@ pg_attribute_aclmask_ext(Oid table_oid, AttrNumber attnum, Oid roleid,
 			ereport(ERROR,
 					(errcode(ERRCODE_UNDEFINED_COLUMN),
 					 errmsg("attribute %d of relation with OID %u does not exist",
-							attnum, table_oid)));
+							attphysnum, table_oid)));
 	}
 
-	aclDatum = SysCacheGetAttr(ATTNUM, attTuple, Anum_pg_attribute_attacl,
+	aclDatum = SysCacheGetAttr(ATTPHYSNUM, attTuple, Anum_pg_attribute_attacl,
 							   &isNull);
 
 	/*
@@ -4875,10 +4875,10 @@ pg_type_aclmask(Oid type_oid, Oid roleid, AclMode mask, AclMaskHow how)
  * column are considered here.
  */
 AclResult
-pg_attribute_aclcheck(Oid table_oid, AttrNumber attnum,
+pg_attribute_aclcheck(Oid table_oid, AttrNumber attphysnum,
 					  Oid roleid, AclMode mode)
 {
-	return pg_attribute_aclcheck_ext(table_oid, attnum, roleid, mode, NULL);
+	return pg_attribute_aclcheck_ext(table_oid, attphysnum, roleid, mode, NULL);
 }
 
 
@@ -4889,10 +4889,10 @@ pg_attribute_aclcheck(Oid table_oid, AttrNumber attnum,
  * callers to avoid the missing attribute ERROR when is_missing is non-NULL.
  */
 AclResult
-pg_attribute_aclcheck_ext(Oid table_oid, AttrNumber attnum,
+pg_attribute_aclcheck_ext(Oid table_oid, AttrNumber attphysnum,
 						  Oid roleid, AclMode mode, bool *is_missing)
 {
-	if (pg_attribute_aclmask_ext(table_oid, attnum, roleid, mode,
+	if (pg_attribute_aclmask_ext(table_oid, attphysnum, roleid, mode,
 								 ACLMASK_ANY, is_missing) != 0)
 		return ACLCHECK_OK;
 	else
@@ -4953,7 +4953,7 @@ pg_attribute_aclcheck_all(Oid table_oid, Oid roleid, AclMode mode,
 		HeapTuple	attTuple;
 		AclMode		attmask;
 
-		attTuple = SearchSysCache2(ATTNUM,
+		attTuple = SearchSysCache2(ATTPHYSNUM,
 								   ObjectIdGetDatum(table_oid),
 								   Int16GetDatum(curr_att));
 		if (!HeapTupleIsValid(attTuple))
@@ -6025,7 +6025,7 @@ recordExtObjInitPriv(Oid objoid, Oid classoid)
 				HeapTuple	attTuple;
 				Datum		attaclDatum;
 
-				attTuple = SearchSysCache2(ATTNUM,
+				attTuple = SearchSysCache2(ATTPHYSNUM,
 										   ObjectIdGetDatum(objoid),
 										   Int16GetDatum(curr_att));
 
@@ -6039,7 +6039,7 @@ recordExtObjInitPriv(Oid objoid, Oid classoid)
 					continue;
 				}
 
-				attaclDatum = SysCacheGetAttr(ATTNUM, attTuple,
+				attaclDatum = SysCacheGetAttr(ATTPHYSNUM, attTuple,
 											  Anum_pg_attribute_attacl,
 											  &isNull);
 
@@ -6318,7 +6318,7 @@ removeExtObjInitPriv(Oid objoid, Oid classoid)
 			{
 				HeapTuple	attTuple;
 
-				attTuple = SearchSysCache2(ATTNUM,
+				attTuple = SearchSysCache2(ATTPHYSNUM,
 										   ObjectIdGetDatum(objoid),
 										   Int16GetDatum(curr_att));
 
diff --git a/src/backend/catalog/catalog.c b/src/backend/catalog/catalog.c
index e784538aae..44b4b03cac 100644
--- a/src/backend/catalog/catalog.c
+++ b/src/backend/catalog/catalog.c
@@ -628,7 +628,7 @@ pg_nextoid(PG_FUNCTION_ARGS)
 						NameStr(*attname), RelationGetRelationName(rel))));
 
 	attform = ((Form_pg_attribute) GETSTRUCT(atttuple));
-	attno = attform->attnum;
+	attno = attform->attphysnum;
 
 	if (attform->atttypid != OIDOID)
 		ereport(ERROR,
diff --git a/src/backend/catalog/genbki.pl b/src/backend/catalog/genbki.pl
index 17b2c5e3f3..f1d33dd949 100644
--- a/src/backend/catalog/genbki.pl
+++ b/src/backend/catalog/genbki.pl
@@ -508,10 +508,10 @@ EOM
 	print $bki "\n (\n";
 	my $schema = $catalog->{columns};
 	my %attnames;
-	my $attnum = 0;
+	my $attphysnum = 0;
 	foreach my $column (@$schema)
 	{
-		$attnum++;
+		$attphysnum++;
 		my $attname = $column->{name};
 		my $atttype = $column->{type};
 
@@ -537,12 +537,12 @@ EOM
 		}
 
 		# Emit Anum_* constants
-		printf $def "#define Anum_%s_%s %s\n", $catname, $attname, $attnum;
+		printf $def "#define Anum_%s_%s %s\n", $catname, $attname, $attphysnum;
 	}
 	print $bki "\n )\n";
 
 	# Emit Natts_* constant
-	print $def "\n#define Natts_$catname $attnum\n\n";
+	print $def "\n#define Natts_$catname $attphysnum\n\n";
 
 	# Emit client code copied from source header
 	foreach my $line (@{ $catalog->{client_code} })
@@ -845,13 +845,13 @@ sub gen_pg_attribute
 		push @tables_needing_macros, $table_name;
 
 		# Generate entries for user attributes.
-		my $attnum          = 0;
+		my $attphysnum          = 0;
 		my $priorfixedwidth = 1;
 		foreach my $attr (@{ $table->{columns} })
 		{
-			$attnum++;
+			$attphysnum++;
 			my %row;
-			$row{attnum}   = $attnum;
+			$row{attphysnum}   = $attphysnum;
 			$row{attrelid} = $table->{relation_oid};
 
 			morph_row_for_pgattr(\%row, $schema, $attr, $priorfixedwidth);
@@ -875,7 +875,7 @@ sub gen_pg_attribute
 		# We only need postgres.bki entries, not schemapg.h entries.
 		if ($table->{bootstrap})
 		{
-			$attnum = 0;
+			$attphysnum = 0;
 			my @SYS_ATTRS = (
 				{ name => 'ctid',     type => 'tid' },
 				{ name => 'xmin',     type => 'xid' },
@@ -885,9 +885,9 @@ sub gen_pg_attribute
 				{ name => 'tableoid', type => 'oid' });
 			foreach my $attr (@SYS_ATTRS)
 			{
-				$attnum--;
+				$attphysnum--;
 				my %row;
-				$row{attnum}        = $attnum;
+				$row{attphysnum}        = $attphysnum;
 				$row{attrelid}      = $table->{relation_oid};
 				$row{attstattarget} = '0';
 
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index 1803194db9..ed9929e67a 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -142,7 +142,7 @@ static const FormData_pg_attribute a1 = {
 	.attname = {"ctid"},
 	.atttypid = TIDOID,
 	.attlen = sizeof(ItemPointerData),
-	.attnum = SelfItemPointerAttributeNumber,
+	.attphysnum = SelfItemPointerAttributeNumber,
 	.attcacheoff = -1,
 	.atttypmod = -1,
 	.attbyval = false,
@@ -156,7 +156,7 @@ static const FormData_pg_attribute a2 = {
 	.attname = {"xmin"},
 	.atttypid = XIDOID,
 	.attlen = sizeof(TransactionId),
-	.attnum = MinTransactionIdAttributeNumber,
+	.attphysnum = MinTransactionIdAttributeNumber,
 	.attcacheoff = -1,
 	.atttypmod = -1,
 	.attbyval = true,
@@ -170,7 +170,7 @@ static const FormData_pg_attribute a3 = {
 	.attname = {"cmin"},
 	.atttypid = CIDOID,
 	.attlen = sizeof(CommandId),
-	.attnum = MinCommandIdAttributeNumber,
+	.attphysnum = MinCommandIdAttributeNumber,
 	.attcacheoff = -1,
 	.atttypmod = -1,
 	.attbyval = true,
@@ -184,7 +184,7 @@ static const FormData_pg_attribute a4 = {
 	.attname = {"xmax"},
 	.atttypid = XIDOID,
 	.attlen = sizeof(TransactionId),
-	.attnum = MaxTransactionIdAttributeNumber,
+	.attphysnum = MaxTransactionIdAttributeNumber,
 	.attcacheoff = -1,
 	.atttypmod = -1,
 	.attbyval = true,
@@ -198,7 +198,7 @@ static const FormData_pg_attribute a5 = {
 	.attname = {"cmax"},
 	.atttypid = CIDOID,
 	.attlen = sizeof(CommandId),
-	.attnum = MaxCommandIdAttributeNumber,
+	.attphysnum = MaxCommandIdAttributeNumber,
 	.attcacheoff = -1,
 	.atttypmod = -1,
 	.attbyval = true,
@@ -218,7 +218,7 @@ static const FormData_pg_attribute a6 = {
 	.attname = {"tableoid"},
 	.atttypid = OIDOID,
 	.attlen = sizeof(Oid),
-	.attnum = TableOidAttributeNumber,
+	.attphysnum = TableOidAttributeNumber,
 	.attcacheoff = -1,
 	.atttypmod = -1,
 	.attbyval = true,
@@ -731,7 +731,7 @@ InsertPgAttributeTuples(Relation pg_attribute_rel,
 		slot[slotCount]->tts_values[Anum_pg_attribute_atttypid - 1] = ObjectIdGetDatum(attrs->atttypid);
 		slot[slotCount]->tts_values[Anum_pg_attribute_attstattarget - 1] = Int32GetDatum(attrs->attstattarget);
 		slot[slotCount]->tts_values[Anum_pg_attribute_attlen - 1] = Int16GetDatum(attrs->attlen);
-		slot[slotCount]->tts_values[Anum_pg_attribute_attnum - 1] = Int16GetDatum(attrs->attnum);
+		slot[slotCount]->tts_values[Anum_pg_attribute_attphysnum - 1] = Int16GetDatum(attrs->attphysnum);
 		slot[slotCount]->tts_values[Anum_pg_attribute_attndims - 1] = Int32GetDatum(attrs->attndims);
 		slot[slotCount]->tts_values[Anum_pg_attribute_attcacheoff - 1] = Int32GetDatum(-1);
 		slot[slotCount]->tts_values[Anum_pg_attribute_atttypmod - 1] = Int32GetDatum(attrs->atttypmod);
@@ -1578,7 +1578,7 @@ DeleteAttributeTuples(Oid relid)
 				BTEqualStrategyNumber, F_OIDEQ,
 				ObjectIdGetDatum(relid));
 
-	scan = systable_beginscan(attrel, AttributeRelidNumIndexId, true,
+	scan = systable_beginscan(attrel, AttributeRelidPhysNumIndexId, true,
 							  NULL, 1, key);
 
 	/* Delete all the matching tuples */
@@ -1615,11 +1615,11 @@ DeleteSystemAttributeTuples(Oid relid)
 				BTEqualStrategyNumber, F_OIDEQ,
 				ObjectIdGetDatum(relid));
 	ScanKeyInit(&key[1],
-				Anum_pg_attribute_attnum,
+				Anum_pg_attribute_attphysnum,
 				BTLessEqualStrategyNumber, F_INT2LE,
 				Int16GetDatum(0));
 
-	scan = systable_beginscan(attrel, AttributeRelidNumIndexId, true,
+	scan = systable_beginscan(attrel, AttributeRelidPhysNumIndexId, true,
 							  NULL, 2, key);
 
 	/* Delete all the matching tuples */
@@ -1640,7 +1640,7 @@ DeleteSystemAttributeTuples(Oid relid)
  * is handled by dependency.c.)
  */
 void
-RemoveAttributeById(Oid relid, AttrNumber attnum)
+RemoveAttributeById(Oid relid, AttrNumber attphysnum)
 {
 	Relation	rel;
 	Relation	attr_rel;
@@ -1658,15 +1658,15 @@ RemoveAttributeById(Oid relid, AttrNumber attnum)
 
 	attr_rel = table_open(AttributeRelationId, RowExclusiveLock);
 
-	tuple = SearchSysCacheCopy2(ATTNUM,
+	tuple = SearchSysCacheCopy2(ATTPHYSNUM,
 								ObjectIdGetDatum(relid),
-								Int16GetDatum(attnum));
+								Int16GetDatum(attphysnum));
 	if (!HeapTupleIsValid(tuple))	/* shouldn't happen */
 		elog(ERROR, "cache lookup failed for attribute %d of relation %u",
-			 attnum, relid);
+			 attphysnum, relid);
 	attStruct = (Form_pg_attribute) GETSTRUCT(tuple);
 
-	if (attnum < 0)
+	if (attphysnum < 0)
 	{
 		/* System attribute (probably OID) ... just delete the row */
 
@@ -1703,7 +1703,7 @@ RemoveAttributeById(Oid relid, AttrNumber attnum)
 		 * Change the column name to something that isn't likely to conflict
 		 */
 		snprintf(newattname, sizeof(newattname),
-				 "........pg.dropped.%d........", attnum);
+				 "........pg.dropped.%d........", attphysnum);
 		namestrcpy(&(attStruct->attname), newattname);
 
 		/* clear the missing value if any */
@@ -1740,8 +1740,8 @@ RemoveAttributeById(Oid relid, AttrNumber attnum)
 
 	table_close(attr_rel, RowExclusiveLock);
 
-	if (attnum > 0)
-		RemoveStatistics(relid, attnum);
+	if (attphysnum > 0)
+		RemoveStatistics(relid, attphysnum);
 
 	relation_close(rel, NoLock);
 }
@@ -1941,7 +1941,7 @@ RelationClearMissing(Relation rel)
 	Relation	attr_rel;
 	Oid			relid = RelationGetRelid(rel);
 	int			natts = RelationGetNumberOfAttributes(rel);
-	int			attnum;
+	int			attphysnum;
 	Datum		repl_val[Natts_pg_attribute];
 	bool		repl_null[Natts_pg_attribute];
 	bool		repl_repl[Natts_pg_attribute];
@@ -1964,14 +1964,14 @@ RelationClearMissing(Relation rel)
 	attr_rel = table_open(AttributeRelationId, RowExclusiveLock);
 
 	/* process each non-system attribute, including any dropped columns */
-	for (attnum = 1; attnum <= natts; attnum++)
+	for (attphysnum = 1; attphysnum <= natts; attphysnum++)
 	{
-		tuple = SearchSysCache2(ATTNUM,
+		tuple = SearchSysCache2(ATTPHYSNUM,
 								ObjectIdGetDatum(relid),
-								Int16GetDatum(attnum));
+								Int16GetDatum(attphysnum));
 		if (!HeapTupleIsValid(tuple))	/* shouldn't happen */
 			elog(ERROR, "cache lookup failed for attribute %d of relation %u",
-				 attnum, relid);
+				 attphysnum, relid);
 
 		attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
 
@@ -2201,7 +2201,7 @@ StoreConstraints(Relation rel, List *cooked_constraints, bool is_internal)
 		switch (con->contype)
 		{
 			case CONSTR_DEFAULT:
-				con->conoid = StoreAttrDefault(rel, con->attnum, con->expr,
+				con->conoid = StoreAttrDefault(rel, con->attphysnum, con->expr,
 											   is_internal, false);
 				break;
 			case CONSTR_CHECK:
@@ -2301,7 +2301,7 @@ AddRelationNewConstraints(Relation rel,
 	foreach(cell, newColDefaults)
 	{
 		RawColumnDefault *colDef = (RawColumnDefault *) lfirst(cell);
-		Form_pg_attribute atp = TupleDescAttr(rel->rd_att, colDef->attnum - 1);
+		Form_pg_attribute atp = TupleDescAttr(rel->rd_att, colDef->attphysnum - 1);
 		Oid			defOid;
 
 		expr = cookDefault(pstate, colDef->raw_default,
@@ -2331,14 +2331,14 @@ AddRelationNewConstraints(Relation rel,
 		if (colDef->missingMode && contain_volatile_functions((Node *) expr))
 			colDef->missingMode = false;
 
-		defOid = StoreAttrDefault(rel, colDef->attnum, expr, is_internal,
+		defOid = StoreAttrDefault(rel, colDef->attphysnum, expr, is_internal,
 								  colDef->missingMode);
 
 		cooked = (CookedConstraint *) palloc(sizeof(CookedConstraint));
 		cooked->contype = CONSTR_DEFAULT;
 		cooked->conoid = defOid;
 		cooked->name = NULL;
-		cooked->attnum = colDef->attnum;
+		cooked->attphysnum = colDef->attphysnum;
 		cooked->expr = expr;
 		cooked->skip_validation = false;
 		cooked->is_local = is_local;
@@ -2469,7 +2469,7 @@ AddRelationNewConstraints(Relation rel,
 		cooked->contype = CONSTR_CHECK;
 		cooked->conoid = constrOid;
 		cooked->name = ccname;
-		cooked->attnum = 0;
+		cooked->attphysnum = 0;
 		cooked->expr = expr;
 		cooked->skip_validation = cdef->skip_validation;
 		cooked->is_local = is_local;
@@ -2695,23 +2695,23 @@ check_nested_generated_walker(Node *node, void *context)
 	{
 		Var		   *var = (Var *) node;
 		Oid			relid;
-		AttrNumber	attnum;
+		AttrNumber	attphysnum;
 
 		relid = rt_fetch(var->varno, pstate->p_rtable)->relid;
 		if (!OidIsValid(relid))
 			return false;		/* XXX shouldn't we raise an error? */
 
-		attnum = var->varattno;
+		attphysnum = var->varattno;
 
-		if (attnum > 0 && get_attgenerated(relid, attnum))
+		if (attphysnum > 0 && get_attgenerated(relid, attphysnum))
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
 					 errmsg("cannot use generated column \"%s\" in column generation expression",
-							get_attname(relid, attnum, false)),
+							get_attname(relid, attphysnum, false)),
 					 errdetail("A generated column cannot reference another generated column."),
 					 parser_errposition(pstate, var->location)));
 		/* A whole-row Var is necessarily self-referential, so forbid it */
-		if (attnum == 0)
+		if (attphysnum == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
 					 errmsg("cannot use whole-row variable in column generation expression"),
@@ -2899,11 +2899,11 @@ CopyStatistics(Oid fromrelid, Oid torelid)
 /*
  * RemoveStatistics --- remove entries in pg_statistic for a rel or column
  *
- * If attnum is zero, remove all entries for rel; else remove only the one(s)
+ * If attphysnum is zero, remove all entries for rel; else remove only the one(s)
  * for that column.
  */
 void
-RemoveStatistics(Oid relid, AttrNumber attnum)
+RemoveStatistics(Oid relid, AttrNumber attphysnum)
 {
 	Relation	pgstatistic;
 	SysScanDesc scan;
@@ -2918,21 +2918,21 @@ RemoveStatistics(Oid relid, AttrNumber attnum)
 				BTEqualStrategyNumber, F_OIDEQ,
 				ObjectIdGetDatum(relid));
 
-	if (attnum == 0)
+	if (attphysnum == 0)
 		nkeys = 1;
 	else
 	{
 		ScanKeyInit(&key[1],
 					Anum_pg_statistic_staattnum,
 					BTEqualStrategyNumber, F_INT2EQ,
-					Int16GetDatum(attnum));
+					Int16GetDatum(attphysnum));
 		nkeys = 2;
 	}
 
 	scan = systable_beginscan(pgstatistic, StatisticRelidAttnumInhIndexId, true,
 							  NULL, nkeys, key);
 
-	/* we must loop even when attnum != 0, in case of inherited stats */
+	/* we must loop even when attphysnum != 0, in case of inherited stats */
 	while (HeapTupleIsValid(tuple = systable_getnext(scan)))
 		CatalogTupleDelete(pgstatistic, &tuple->t_self);
 
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index bdd3c34841..c514e3b622 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -231,25 +231,25 @@ index_check_primary_key(Relation heapRel,
 	 */
 	for (i = 0; i < indexInfo->ii_NumIndexKeyAttrs; i++)
 	{
-		AttrNumber	attnum = indexInfo->ii_IndexAttrNumbers[i];
+		AttrNumber	attphysnum = indexInfo->ii_IndexAttrNumbers[i];
 		HeapTuple	atttuple;
 		Form_pg_attribute attform;
 
-		if (attnum == 0)
+		if (attphysnum == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 					 errmsg("primary keys cannot be expressions")));
 
 		/* System attributes are never null, so no need to check */
-		if (attnum < 0)
+		if (attphysnum < 0)
 			continue;
 
-		atttuple = SearchSysCache2(ATTNUM,
+		atttuple = SearchSysCache2(ATTPHYSNUM,
 								   ObjectIdGetDatum(RelationGetRelid(heapRel)),
-								   Int16GetDatum(attnum));
+								   Int16GetDatum(attphysnum));
 		if (!HeapTupleIsValid(atttuple))
 			elog(ERROR, "cache lookup failed for attribute %d of relation %u",
-				 attnum, RelationGetRelid(heapRel));
+				 attphysnum, RelationGetRelid(heapRel));
 		attform = (Form_pg_attribute) GETSTRUCT(atttuple);
 
 		if (!attform->attnotnull)
@@ -310,7 +310,7 @@ ConstructTupleDescriptor(Relation heapRelation,
 		Oid			keyType;
 
 		MemSet(to, 0, ATTRIBUTE_FIXED_PART_SIZE);
-		to->attnum = i + 1;
+		to->attphysnum = i + 1;
 		to->attstattarget = -1;
 		to->attcacheoff = -1;
 		to->attislocal = true;
@@ -1770,7 +1770,7 @@ index_concurrently_swap(Oid newIndexId, Oid oldIndexId, const char *oldName)
 					Anum_pg_attribute_attrelid,
 					BTEqualStrategyNumber, F_OIDEQ,
 					ObjectIdGetDatum(newIndexId));
-		scan = systable_beginscan(pg_attribute, AttributeRelidNumIndexId,
+		scan = systable_beginscan(pg_attribute, AttributeRelidPhysNumIndexId,
 								  true, NULL, 1, key);
 
 		while (HeapTupleIsValid((attrTuple = systable_getnext(scan))))
@@ -1789,7 +1789,7 @@ index_concurrently_swap(Oid newIndexId, Oid oldIndexId, const char *oldName)
 			/*
 			 * Get attstattarget from the old index and refresh the new value.
 			 */
-			attstattarget = get_attstattarget(oldIndexId, att->attnum);
+			attstattarget = get_attstattarget(oldIndexId, att->attphysnum);
 
 			/* no need for a refresh if both match */
 			if (attstattarget == att->attstattarget)
diff --git a/src/backend/catalog/indexing.c b/src/backend/catalog/indexing.c
index 0b92093322..6c5052c0de 100644
--- a/src/backend/catalog/indexing.c
+++ b/src/backend/catalog/indexing.c
@@ -191,11 +191,11 @@ CatalogTupleCheckConstraints(Relation heapRel, HeapTuple tup)
 		TupleDesc	tupdesc = RelationGetDescr(heapRel);
 		bits8	   *bp = tup->t_data->t_bits;
 
-		for (int attnum = 0; attnum < tupdesc->natts; attnum++)
+		for (int attphysnum = 0; attphysnum < tupdesc->natts; attphysnum++)
 		{
-			Form_pg_attribute thisatt = TupleDescAttr(tupdesc, attnum);
+			Form_pg_attribute thisatt = TupleDescAttr(tupdesc, attphysnum);
 
-			Assert(!(thisatt->attnotnull && att_isnull(attnum, bp)));
+			Assert(!(thisatt->attnotnull && att_isnull(attphysnum, bp)));
 		}
 	}
 }
diff --git a/src/backend/catalog/information_schema.sql b/src/backend/catalog/information_schema.sql
index 18725a02d1..90004ea3bc 100644
--- a/src/backend/catalog/information_schema.sql
+++ b/src/backend/catalog/information_schema.sql
@@ -293,7 +293,7 @@ CREATE VIEW attributes AS
            CAST(nc.nspname AS sql_identifier) AS udt_schema,
            CAST(c.relname AS sql_identifier) AS udt_name,
            CAST(a.attname AS sql_identifier) AS attribute_name,
-           CAST(a.attnum AS cardinal_number) AS ordinal_position,
+           CAST(a.attphysnum AS cardinal_number) AS ordinal_position,
            CAST(pg_get_expr(ad.adbin, ad.adrelid) AS character_data) AS attribute_default,
            CAST(CASE WHEN a.attnotnull OR (t.typtype = 'd' AND t.typnotnull) THEN 'NO' ELSE 'YES' END
              AS yes_or_no)
@@ -359,16 +359,16 @@ CREATE VIEW attributes AS
            CAST(null AS sql_identifier) AS scope_name,
 
            CAST(null AS cardinal_number) AS maximum_cardinality,
-           CAST(a.attnum AS sql_identifier) AS dtd_identifier,
+           CAST(a.attphysnum AS sql_identifier) AS dtd_identifier,
            CAST('NO' AS yes_or_no) AS is_derived_reference_attribute
 
-    FROM (pg_attribute a LEFT JOIN pg_attrdef ad ON attrelid = adrelid AND attnum = adnum)
+    FROM (pg_attribute a LEFT JOIN pg_attrdef ad ON attrelid = adrelid AND attphysnum = adnum)
          JOIN (pg_class c JOIN pg_namespace nc ON (c.relnamespace = nc.oid)) ON a.attrelid = c.oid
          JOIN (pg_type t JOIN pg_namespace nt ON (t.typnamespace = nt.oid)) ON a.atttypid = t.oid
          LEFT JOIN (pg_collation co JOIN pg_namespace nco ON (co.collnamespace = nco.oid))
            ON a.attcollation = co.oid AND (nco.nspname, co.collname) <> ('pg_catalog', 'default')
 
-    WHERE a.attnum > 0 AND NOT a.attisdropped
+    WHERE a.attphysnum > 0 AND NOT a.attisdropped
           AND c.relkind IN ('c')
           AND (pg_has_role(c.relowner, 'USAGE')
                OR has_type_privilege(c.reltype, 'USAGE'));
@@ -449,13 +449,13 @@ CREATE VIEW check_constraints AS
 
     SELECT CAST(current_database() AS sql_identifier) AS constraint_catalog,
            CAST(n.nspname AS sql_identifier) AS constraint_schema,
-           CAST(CAST(n.oid AS text) || '_' || CAST(r.oid AS text) || '_' || CAST(a.attnum AS text) || '_not_null' AS sql_identifier) AS constraint_name, -- XXX
+           CAST(CAST(n.oid AS text) || '_' || CAST(r.oid AS text) || '_' || CAST(a.attphysnum AS text) || '_not_null' AS sql_identifier) AS constraint_name, -- XXX
            CAST(a.attname || ' IS NOT NULL' AS character_data)
              AS check_clause
     FROM pg_namespace n, pg_class r, pg_attribute a
     WHERE n.oid = r.relnamespace
       AND r.oid = a.attrelid
-      AND a.attnum > 0
+      AND a.attphysnum > 0
       AND NOT a.attisdropped
       AND a.attnotnull
       AND r.relkind IN ('r', 'p')
@@ -519,14 +519,14 @@ CREATE VIEW column_column_usage AS
     WHERE n.oid = c.relnamespace
           AND c.oid = ac.attrelid
           AND c.oid = ad.attrelid
-          AND ac.attnum <> ad.attnum
+          AND ac.attphysnum <> ad.attphysnum
           AND ad.attrelid = atd.adrelid
-          AND ad.attnum = atd.adnum
+          AND ad.attphysnum = atd.adnum
           AND d.classid = 'pg_catalog.pg_attrdef'::regclass
           AND d.refclassid = 'pg_catalog.pg_class'::regclass
           AND d.objid = atd.oid
           AND d.refobjid = ac.attrelid
-          AND d.refobjsubid = ac.attnum
+          AND d.refobjsubid = ac.attphysnum
           AND ad.attgenerated <> ''
           AND pg_has_role(c.relowner, 'USAGE');
 
@@ -556,7 +556,7 @@ CREATE VIEW column_domain_usage AS
           AND a.atttypid = t.oid
           AND t.typtype = 'd'
           AND c.relkind IN ('r', 'v', 'f', 'p')
-          AND a.attnum > 0
+          AND a.attphysnum > 0
           AND NOT a.attisdropped
           AND pg_has_role(t.typowner, 'USAGE');
 
@@ -598,7 +598,7 @@ CREATE VIEW column_privileges AS
                 ) pr_c (oid, relname, relnamespace, relowner, grantor, grantee, prtype, grantable),
                 pg_attribute a
            WHERE a.attrelid = pr_c.oid
-                 AND a.attnum > 0
+                 AND a.attphysnum > 0
                  AND NOT a.attisdropped
            UNION
            SELECT pr_a.grantor,
@@ -611,7 +611,7 @@ CREATE VIEW column_privileges AS
                   c.relowner
            FROM (SELECT attrelid, attname, (aclexplode(coalesce(attacl, acldefault('c', relowner)))).*
                  FROM pg_attribute a JOIN pg_class cc ON (a.attrelid = cc.oid)
-                 WHERE attnum > 0
+                 WHERE attphysnum > 0
                        AND NOT attisdropped
                 ) pr_a (attrelid, attname, grantor, grantee, prtype, grantable),
                 pg_class c
@@ -659,7 +659,7 @@ CREATE VIEW column_udt_usage AS
     WHERE a.attrelid = c.oid
           AND a.atttypid = t.oid
           AND nc.oid = c.relnamespace
-          AND a.attnum > 0 AND NOT a.attisdropped
+          AND a.attphysnum > 0 AND NOT a.attisdropped
           AND c.relkind in ('r', 'v', 'f', 'p')
           AND pg_has_role(coalesce(bt.typowner, t.typowner), 'USAGE');
 
@@ -676,7 +676,7 @@ CREATE VIEW columns AS
            CAST(nc.nspname AS sql_identifier) AS table_schema,
            CAST(c.relname AS sql_identifier) AS table_name,
            CAST(a.attname AS sql_identifier) AS column_name,
-           CAST(a.attnum AS cardinal_number) AS ordinal_position,
+           CAST(a.attphysnum AS cardinal_number) AS ordinal_position,
            CAST(CASE WHEN a.attgenerated = '' THEN pg_get_expr(ad.adbin, ad.adrelid) END AS character_data) AS column_default,
            CAST(CASE WHEN a.attnotnull OR (t.typtype = 'd' AND t.typnotnull) THEN 'NO' ELSE 'YES' END
              AS yes_or_no)
@@ -755,7 +755,7 @@ CREATE VIEW columns AS
            CAST(null AS sql_identifier) AS scope_name,
 
            CAST(null AS cardinal_number) AS maximum_cardinality,
-           CAST(a.attnum AS sql_identifier) AS dtd_identifier,
+           CAST(a.attphysnum AS sql_identifier) AS dtd_identifier,
            CAST('NO' AS yes_or_no) AS is_self_referencing,
 
            CAST(CASE WHEN a.attidentity IN ('a', 'd') THEN 'YES' ELSE 'NO' END AS yes_or_no) AS is_identity,
@@ -771,10 +771,10 @@ CREATE VIEW columns AS
 
            CAST(CASE WHEN c.relkind IN ('r', 'p') OR
                           (c.relkind IN ('v', 'f') AND
-                           pg_column_is_updatable(c.oid, a.attnum, false))
+                           pg_column_is_updatable(c.oid, a.attphysnum, false))
                 THEN 'YES' ELSE 'NO' END AS yes_or_no) AS is_updatable
 
-    FROM (pg_attribute a LEFT JOIN pg_attrdef ad ON attrelid = adrelid AND attnum = adnum)
+    FROM (pg_attribute a LEFT JOIN pg_attrdef ad ON attrelid = adrelid AND attphysnum = adnum)
          JOIN (pg_class c JOIN pg_namespace nc ON (c.relnamespace = nc.oid)) ON a.attrelid = c.oid
          JOIN (pg_type t JOIN pg_namespace nt ON (t.typnamespace = nt.oid)) ON a.atttypid = t.oid
          LEFT JOIN (pg_type bt JOIN pg_namespace nbt ON (bt.typnamespace = nbt.oid))
@@ -782,15 +782,15 @@ CREATE VIEW columns AS
          LEFT JOIN (pg_collation co JOIN pg_namespace nco ON (co.collnamespace = nco.oid))
            ON a.attcollation = co.oid AND (nco.nspname, co.collname) <> ('pg_catalog', 'default')
          LEFT JOIN (pg_depend dep JOIN pg_sequence seq ON (dep.classid = 'pg_class'::regclass AND dep.objid = seq.seqrelid AND dep.deptype = 'i'))
-           ON (dep.refclassid = 'pg_class'::regclass AND dep.refobjid = c.oid AND dep.refobjsubid = a.attnum)
+           ON (dep.refclassid = 'pg_class'::regclass AND dep.refobjid = c.oid AND dep.refobjsubid = a.attphysnum)
 
     WHERE (NOT pg_is_other_temp_schema(nc.oid))
 
-          AND a.attnum > 0 AND NOT a.attisdropped
+          AND a.attphysnum > 0 AND NOT a.attisdropped
           AND c.relkind IN ('r', 'v', 'f', 'p')
 
           AND (pg_has_role(c.relowner, 'USAGE')
-               OR has_column_privilege(c.oid, a.attnum,
+               OR has_column_privilege(c.oid, a.attphysnum,
                                        'SELECT, INSERT, UPDATE, REFERENCES'));
 
 GRANT SELECT ON columns TO PUBLIC;
@@ -818,7 +818,7 @@ CREATE VIEW constraint_column_usage AS
             AND r.oid = a.attrelid
             AND d.refclassid = 'pg_catalog.pg_class'::regclass
             AND d.refobjid = r.oid
-            AND d.refobjsubid = a.attnum
+            AND d.refobjsubid = a.attphysnum
             AND d.classid = 'pg_catalog.pg_constraint'::regclass
             AND d.objid = c.oid
             AND c.connamespace = nc.oid
@@ -836,7 +836,7 @@ CREATE VIEW constraint_column_usage AS
             AND r.oid = a.attrelid
             AND nc.oid = c.connamespace
             AND r.oid = CASE c.contype WHEN 'f' THEN c.confrelid ELSE c.conrelid END
-            AND a.attnum = ANY (CASE c.contype WHEN 'f' THEN c.confkey ELSE c.conkey END)
+            AND a.attphysnum = ANY (CASE c.contype WHEN 'f' THEN c.confkey ELSE c.conkey END)
             AND NOT a.attisdropped
             AND c.contype IN ('p', 'u', 'f')
             AND r.relkind IN ('r', 'p')
@@ -1095,10 +1095,10 @@ CREATE VIEW key_column_usage AS
                 AND r.relkind IN ('r', 'p')
                 AND (NOT pg_is_other_temp_schema(nr.oid)) ) AS ss
     WHERE ss.roid = a.attrelid
-          AND a.attnum = (ss.x).x
+          AND a.attphysnum = (ss.x).x
           AND NOT a.attisdropped
           AND (pg_has_role(relowner, 'USAGE')
-               OR has_column_privilege(roid, a.attnum,
+               OR has_column_privilege(roid, a.attphysnum,
                                        'SELECT, INSERT, UPDATE, REFERENCES'));
 
 GRANT SELECT ON key_column_usage TO PUBLIC;
@@ -1352,7 +1352,7 @@ CREATE VIEW routine_column_usage AS
           AND t.relnamespace = nt.oid
           AND t.relkind IN ('r', 'v', 'f', 'p')
           AND t.oid = a.attrelid
-          AND d.refobjsubid = a.attnum
+          AND d.refobjsubid = a.attphysnum
           AND pg_has_role(t.relowner, 'USAGE');
 
 GRANT SELECT ON routine_column_usage TO PUBLIC;
@@ -1867,7 +1867,7 @@ CREATE VIEW table_constraints AS
 
     SELECT CAST(current_database() AS sql_identifier) AS constraint_catalog,
            CAST(nr.nspname AS sql_identifier) AS constraint_schema,
-           CAST(CAST(nr.oid AS text) || '_' || CAST(r.oid AS text) || '_' || CAST(a.attnum AS text) || '_not_null' AS sql_identifier) AS constraint_name, -- XXX
+           CAST(CAST(nr.oid AS text) || '_' || CAST(r.oid AS text) || '_' || CAST(a.attphysnum AS text) || '_not_null' AS sql_identifier) AS constraint_name, -- XXX
            CAST(current_database() AS sql_identifier) AS table_catalog,
            CAST(nr.nspname AS sql_identifier) AS table_schema,
            CAST(r.relname AS sql_identifier) AS table_name,
@@ -1884,7 +1884,7 @@ CREATE VIEW table_constraints AS
     WHERE nr.oid = r.relnamespace
           AND r.oid = a.attrelid
           AND a.attnotnull
-          AND a.attnum > 0
+          AND a.attphysnum > 0
           AND NOT a.attisdropped
           AND r.relkind IN ('r', 'p')
           AND (NOT pg_is_other_temp_schema(nr.oid))
@@ -2084,12 +2084,12 @@ CREATE VIEW triggered_update_columns AS
     WHERE n.oid = c.relnamespace
           AND c.oid = t.tgrelid
           AND t.oid = ta.tgoid
-          AND (a.attrelid, a.attnum) = (t.tgrelid, ta.tgattnum)
+          AND (a.attrelid, a.attphysnum) = (t.tgrelid, ta.tgattnum)
           AND NOT t.tgisinternal
           AND (NOT pg_is_other_temp_schema(n.oid))
           AND (pg_has_role(c.relowner, 'USAGE')
                -- SELECT privilege omitted, per SQL standard
-               OR has_column_privilege(c.oid, a.attnum, 'INSERT, UPDATE, REFERENCES') );
+               OR has_column_privilege(c.oid, a.attphysnum, 'INSERT, UPDATE, REFERENCES') );
 
 GRANT SELECT ON triggered_update_columns TO PUBLIC;
 
@@ -2537,7 +2537,7 @@ CREATE VIEW view_column_usage AS
           AND t.relnamespace = nt.oid
           AND t.relkind IN ('r', 'v', 'f', 'p')
           AND t.oid = a.attrelid
-          AND dt.refobjsubid = a.attnum
+          AND dt.refobjsubid = a.attphysnum
           AND pg_has_role(t.relowner, 'USAGE');
 
 GRANT SELECT ON view_column_usage TO PUBLIC;
@@ -2763,11 +2763,11 @@ CREATE VIEW element_types AS
            /* columns, attributes */
            SELECT c.relnamespace, CAST(c.relname AS sql_identifier),
                   CASE WHEN c.relkind = 'c' THEN 'USER-DEFINED TYPE'::text ELSE 'TABLE'::text END,
-                  a.attnum, a.atttypid, a.attcollation
+                  a.attphysnum, a.atttypid, a.attcollation
            FROM pg_class c, pg_attribute a
            WHERE c.oid = a.attrelid
                  AND c.relkind IN ('r', 'v', 'f', 'c', 'p')
-                 AND attnum > 0 AND NOT attisdropped
+                 AND attphysnum > 0 AND NOT attisdropped
 
            UNION ALL
 
@@ -2824,12 +2824,12 @@ CREATE VIEW _pg_foreign_table_columns AS
          pg_attribute a
     WHERE u.oid = c.relowner
           AND (pg_has_role(c.relowner, 'USAGE')
-               OR has_column_privilege(c.oid, a.attnum, 'SELECT, INSERT, UPDATE, REFERENCES'))
+               OR has_column_privilege(c.oid, a.attphysnum, 'SELECT, INSERT, UPDATE, REFERENCES'))
           AND n.oid = c.relnamespace
           AND c.oid = t.ftrelid
           AND c.relkind = 'f'
           AND a.attrelid = c.oid
-          AND a.attnum > 0;
+          AND a.attphysnum > 0;
 
 /*
  * 24.2
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index 8377b4f7d4..e373637651 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -107,10 +107,10 @@ typedef struct
 									 * (name) if the object does not live in a
 									 * namespace */
 	AttrNumber	attnum_oid;		/* attribute number of oid column */
-	AttrNumber	attnum_name;	/* attnum of name field */
-	AttrNumber	attnum_namespace;	/* attnum of namespace field */
-	AttrNumber	attnum_owner;	/* attnum of owner field */
-	AttrNumber	attnum_acl;		/* attnum of acl field */
+	AttrNumber	attnum_name;	/* attphysnum of name field */
+	AttrNumber	attnum_namespace;	/* attphysnum of namespace field */
+	AttrNumber	attnum_owner;	/* attphysnum of owner field */
+	AttrNumber	attnum_acl;		/* attphysnum of acl field */
 	ObjectType	objtype;		/* OBJECT_* of this object type */
 	bool		is_nsp_name_unique; /* can the nsp/name combination (or name
 									 * alone, if there's no namespace) be
@@ -1520,7 +1520,7 @@ get_object_address_attribute(ObjectType objtype, List *object,
 	Oid			reloid;
 	Relation	relation;
 	const char *attname;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 
 	/* Extract relation name and open relation. */
 	if (list_length(object) < 2)
@@ -1534,8 +1534,8 @@ get_object_address_attribute(ObjectType objtype, List *object,
 	reloid = RelationGetRelid(relation);
 
 	/* Look up attribute and construct return value. */
-	attnum = get_attnum(reloid, attname);
-	if (attnum == InvalidAttrNumber)
+	attphysnum = get_attphysnum(reloid, attname);
+	if (attphysnum == InvalidAttrNumber)
 	{
 		if (!missing_ok)
 			ereport(ERROR,
@@ -1552,7 +1552,7 @@ get_object_address_attribute(ObjectType objtype, List *object,
 
 	address.classId = RelationRelationId;
 	address.objectId = reloid;
-	address.objectSubId = attnum;
+	address.objectSubId = attphysnum;
 
 	*relp = relation;
 	return address;
@@ -1571,7 +1571,7 @@ get_object_address_attrdef(ObjectType objtype, List *object,
 	Oid			reloid;
 	Relation	relation;
 	const char *attname;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	TupleDesc	tupdesc;
 	Oid			defoid;
 
@@ -1589,10 +1589,10 @@ get_object_address_attrdef(ObjectType objtype, List *object,
 	tupdesc = RelationGetDescr(relation);
 
 	/* Look up attribute number and fetch the pg_attrdef OID */
-	attnum = get_attnum(reloid, attname);
+	attphysnum = get_attphysnum(reloid, attname);
 	defoid = InvalidOid;
-	if (attnum != InvalidAttrNumber && tupdesc->constr != NULL)
-		defoid = GetAttrDefaultOid(reloid, attnum);
+	if (attphysnum != InvalidAttrNumber && tupdesc->constr != NULL)
+		defoid = GetAttrDefaultOid(reloid, attphysnum);
 	if (!OidIsValid(defoid))
 	{
 		if (!missing_ok)
diff --git a/src/backend/catalog/pg_attrdef.c b/src/backend/catalog/pg_attrdef.c
index c5d4a9912e..8587796e0b 100644
--- a/src/backend/catalog/pg_attrdef.c
+++ b/src/backend/catalog/pg_attrdef.c
@@ -32,7 +32,7 @@
 
 
 /*
- * Store a default expression for column attnum of relation rel.
+ * Store a default expression for column attphysnum of relation rel.
  *
  * Returns the OID of the new pg_attrdef tuple.
  *
@@ -43,7 +43,7 @@
  * in effect be changing existing tuples.
  */
 Oid
-StoreAttrDefault(Relation rel, AttrNumber attnum,
+StoreAttrDefault(Relation rel, AttrNumber attphysnum,
 				 Node *expr, bool is_internal, bool add_column_mode)
 {
 	char	   *adbin;
@@ -73,7 +73,7 @@ StoreAttrDefault(Relation rel, AttrNumber attnum,
 									Anum_pg_attrdef_oid);
 	values[Anum_pg_attrdef_oid - 1] = ObjectIdGetDatum(attrdefOid);
 	values[Anum_pg_attrdef_adrelid - 1] = RelationGetRelid(rel);
-	values[Anum_pg_attrdef_adnum - 1] = attnum;
+	values[Anum_pg_attrdef_adnum - 1] = attphysnum;
 	values[Anum_pg_attrdef_adbin - 1] = CStringGetTextDatum(adbin);
 
 	tuple = heap_form_tuple(adrel->rd_att, values, nulls);
@@ -95,12 +95,12 @@ StoreAttrDefault(Relation rel, AttrNumber attnum,
 	 * exists.
 	 */
 	attrrel = table_open(AttributeRelationId, RowExclusiveLock);
-	atttup = SearchSysCacheCopy2(ATTNUM,
+	atttup = SearchSysCacheCopy2(ATTPHYSNUM,
 								 ObjectIdGetDatum(RelationGetRelid(rel)),
-								 Int16GetDatum(attnum));
+								 Int16GetDatum(attphysnum));
 	if (!HeapTupleIsValid(atttup))
 		elog(ERROR, "cache lookup failed for attribute %d of relation %u",
-			 attnum, RelationGetRelid(rel));
+			 attphysnum, RelationGetRelid(rel));
 	attStruct = (Form_pg_attribute) GETSTRUCT(atttup);
 	attgenerated = attStruct->attgenerated;
 	if (!attStruct->atthasdef)
@@ -136,7 +136,7 @@ StoreAttrDefault(Relation rel, AttrNumber attnum,
 
 			FreeExecutorState(estate);
 
-			defAttStruct = TupleDescAttr(rel->rd_att, attnum - 1);
+			defAttStruct = TupleDescAttr(rel->rd_att, attphysnum - 1);
 
 			if (missingIsNull)
 			{
@@ -179,7 +179,7 @@ StoreAttrDefault(Relation rel, AttrNumber attnum,
 	 */
 	colobject.classId = RelationRelationId;
 	colobject.objectId = RelationGetRelid(rel);
-	colobject.objectSubId = attnum;
+	colobject.objectSubId = attphysnum;
 
 	recordDependencyOn(&defobject, &colobject,
 					   attgenerated ? DEPENDENCY_INTERNAL : DEPENDENCY_AUTO);
@@ -200,7 +200,7 @@ StoreAttrDefault(Relation rel, AttrNumber attnum,
 	 * needs to distinguish.
 	 */
 	InvokeObjectPostCreateHookArg(AttrDefaultRelationId,
-								  RelationGetRelid(rel), attnum, is_internal);
+								  RelationGetRelid(rel), attphysnum, is_internal);
 
 	return attrdefOid;
 }
@@ -213,7 +213,7 @@ StoreAttrDefault(Relation rel, AttrNumber attnum,
  * (If no default, raise error if complain is true, else return quietly.)
  */
 void
-RemoveAttrDefault(Oid relid, AttrNumber attnum,
+RemoveAttrDefault(Oid relid, AttrNumber attphysnum,
 				  DropBehavior behavior, bool complain, bool internal)
 {
 	Relation	attrdef_rel;
@@ -231,7 +231,7 @@ RemoveAttrDefault(Oid relid, AttrNumber attnum,
 	ScanKeyInit(&scankeys[1],
 				Anum_pg_attrdef_adnum,
 				BTEqualStrategyNumber, F_INT2EQ,
-				Int16GetDatum(attnum));
+				Int16GetDatum(attphysnum));
 
 	scan = systable_beginscan(attrdef_rel, AttrDefaultIndexId, true,
 							  NULL, 2, scankeys);
@@ -256,8 +256,8 @@ RemoveAttrDefault(Oid relid, AttrNumber attnum,
 	table_close(attrdef_rel, RowExclusiveLock);
 
 	if (complain && !found)
-		elog(ERROR, "could not find attrdef tuple for relation %u attnum %d",
-			 relid, attnum);
+		elog(ERROR, "could not find attrdef tuple for relation %u attphysnum %d",
+			 relid, attphysnum);
 }
 
 /*
@@ -310,7 +310,7 @@ RemoveAttrDefaultById(Oid attrdefId)
 	/* Fix the pg_attribute row */
 	attr_rel = table_open(AttributeRelationId, RowExclusiveLock);
 
-	tuple = SearchSysCacheCopy2(ATTNUM,
+	tuple = SearchSysCacheCopy2(ATTPHYSNUM,
 								ObjectIdGetDatum(myrelid),
 								Int16GetDatum(myattnum));
 	if (!HeapTupleIsValid(tuple))	/* shouldn't happen */
@@ -339,7 +339,7 @@ RemoveAttrDefaultById(Oid attrdefId)
  * Returns InvalidOid if there is no such pg_attrdef entry.
  */
 Oid
-GetAttrDefaultOid(Oid relid, AttrNumber attnum)
+GetAttrDefaultOid(Oid relid, AttrNumber attphysnum)
 {
 	Oid			result = InvalidOid;
 	Relation	attrdef;
@@ -357,7 +357,7 @@ GetAttrDefaultOid(Oid relid, AttrNumber attnum)
 				Anum_pg_attrdef_adnum,
 				BTEqualStrategyNumber,
 				F_INT2EQ,
-				Int16GetDatum(attnum));
+				Int16GetDatum(attphysnum));
 	scan = systable_beginscan(attrdef, AttrDefaultIndexId, true,
 							  NULL, 2, keys);
 
diff --git a/src/backend/catalog/pg_depend.c b/src/backend/catalog/pg_depend.c
index e86e5e6898..e8a2be6fc7 100644
--- a/src/backend/catalog/pg_depend.c
+++ b/src/backend/catalog/pg_depend.c
@@ -816,7 +816,7 @@ sequenceIsOwned(Oid seqId, char deptype, Oid *tableId, int32 *colId)
  * with the specified dependency type.
  */
 static List *
-getOwnedSequences_internal(Oid relid, AttrNumber attnum, char deptype)
+getOwnedSequences_internal(Oid relid, AttrNumber attphysnum, char deptype)
 {
 	List	   *result = NIL;
 	Relation	depRel;
@@ -834,14 +834,14 @@ getOwnedSequences_internal(Oid relid, AttrNumber attnum, char deptype)
 				Anum_pg_depend_refobjid,
 				BTEqualStrategyNumber, F_OIDEQ,
 				ObjectIdGetDatum(relid));
-	if (attnum)
+	if (attphysnum)
 		ScanKeyInit(&key[2],
 					Anum_pg_depend_refobjsubid,
 					BTEqualStrategyNumber, F_INT4EQ,
-					Int32GetDatum(attnum));
+					Int32GetDatum(attphysnum));
 
 	scan = systable_beginscan(depRel, DependReferenceIndexId, true,
-							  NULL, attnum ? 3 : 2, key);
+							  NULL, attphysnum ? 3 : 2, key);
 
 	while (HeapTupleIsValid(tup = systable_getnext(scan)))
 	{
@@ -884,9 +884,9 @@ getOwnedSequences(Oid relid)
  * Get owned identity sequence, error if not exactly one.
  */
 Oid
-getIdentitySequence(Oid relid, AttrNumber attnum, bool missing_ok)
+getIdentitySequence(Oid relid, AttrNumber attphysnum, bool missing_ok)
 {
-	List	   *seqlist = getOwnedSequences_internal(relid, attnum, DEPENDENCY_INTERNAL);
+	List	   *seqlist = getOwnedSequences_internal(relid, attphysnum, DEPENDENCY_INTERNAL);
 
 	if (list_length(seqlist) > 1)
 		elog(ERROR, "more than one owned sequence found");
diff --git a/src/backend/catalog/pg_publication.c b/src/backend/catalog/pg_publication.c
index c365de3a72..0a8cefe637 100644
--- a/src/backend/catalog/pg_publication.c
+++ b/src/backend/catalog/pg_publication.c
@@ -502,34 +502,34 @@ publication_translate_columns(Relation targetrel, List *columns,
 	foreach(lc, columns)
 	{
 		char	   *colname = strVal(lfirst(lc));
-		AttrNumber	attnum = get_attnum(RelationGetRelid(targetrel), colname);
+		AttrNumber	attphysnum = get_attphysnum(RelationGetRelid(targetrel), colname);
 
-		if (attnum == InvalidAttrNumber)
+		if (attphysnum == InvalidAttrNumber)
 			ereport(ERROR,
 					errcode(ERRCODE_UNDEFINED_COLUMN),
 					errmsg("column \"%s\" of relation \"%s\" does not exist",
 						   colname, RelationGetRelationName(targetrel)));
 
-		if (!AttrNumberIsForUserDefinedAttr(attnum))
+		if (!AttrNumberIsForUserDefinedAttr(attphysnum))
 			ereport(ERROR,
 					errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 					errmsg("cannot reference system column \"%s\" in publication column list",
 						   colname));
 
-		if (TupleDescAttr(tupdesc, attnum - 1)->attgenerated)
+		if (TupleDescAttr(tupdesc, attphysnum - 1)->attgenerated)
 			ereport(ERROR,
 					errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 					errmsg("cannot reference generated column \"%s\" in publication column list",
 						   colname));
 
-		if (bms_is_member(attnum, set))
+		if (bms_is_member(attphysnum, set))
 			ereport(ERROR,
 					errcode(ERRCODE_DUPLICATE_OBJECT),
 					errmsg("duplicate column \"%s\" in publication column list",
 						   colname));
 
-		set = bms_add_member(set, attnum);
-		attarray[n++] = attnum;
+		set = bms_add_member(set, attphysnum);
+		attarray[n++] = attphysnum;
 	}
 
 	/* Be tidy, so that the catalog representation is always sorted */
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index fedaed533b..37b7edc2db 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -245,10 +245,10 @@ CREATE VIEW pg_stats WITH (security_barrier) AS
             WHEN stakind5 = 5 THEN stanumbers5
         END AS elem_count_histogram
     FROM pg_statistic s JOIN pg_class c ON (c.oid = s.starelid)
-         JOIN pg_attribute a ON (c.oid = attrelid AND attnum = s.staattnum)
+         JOIN pg_attribute a ON (c.oid = attrelid AND attphysnum = s.staattnum)
          LEFT JOIN pg_namespace n ON (n.oid = c.relnamespace)
     WHERE NOT attisdropped
-    AND has_column_privilege(c.oid, a.attnum, 'select')
+    AND has_column_privilege(c.oid, a.attphysnum, 'select')
     AND (c.relrowsecurity = false OR NOT row_security_active(c.oid));
 
 REVOKE ALL ON pg_statistic FROM public;
@@ -259,10 +259,10 @@ CREATE VIEW pg_stats_ext WITH (security_barrier) AS
            sn.nspname AS statistics_schemaname,
            s.stxname AS statistics_name,
            pg_get_userbyid(s.stxowner) AS statistics_owner,
-           ( SELECT array_agg(a.attname ORDER BY a.attnum)
+           ( SELECT array_agg(a.attname ORDER BY a.attphysnum)
              FROM unnest(s.stxkeys) k
                   JOIN pg_attribute a
-                       ON (a.attrelid = s.stxrelid AND a.attnum = k)
+                       ON (a.attrelid = s.stxrelid AND a.attphysnum = k)
            ) AS attnames,
            pg_get_statisticsobjdef_expressions(s.oid) as exprs,
            s.stxkind AS kinds,
@@ -288,8 +288,8 @@ CREATE VIEW pg_stats_ext WITH (security_barrier) AS
               ( SELECT 1
                 FROM unnest(stxkeys) k
                      JOIN pg_attribute a
-                          ON (a.attrelid = s.stxrelid AND a.attnum = k)
-                WHERE NOT has_column_privilege(c.oid, a.attnum, 'select') )
+                          ON (a.attrelid = s.stxrelid AND a.attphysnum = k)
+                WHERE NOT has_column_privilege(c.oid, a.attphysnum, 'select') )
     AND (c.relrowsecurity = false OR NOT row_security_active(c.oid));
 
 CREATE VIEW pg_stats_ext_exprs WITH (security_barrier) AS
@@ -369,12 +369,12 @@ CREATE VIEW pg_publication_tables AS
         P.pubname AS pubname,
         N.nspname AS schemaname,
         C.relname AS tablename,
-        ( SELECT array_agg(a.attname ORDER BY a.attnum)
+        ( SELECT array_agg(a.attname ORDER BY a.attphysnum)
           FROM unnest(CASE WHEN GPT.attrs IS NOT NULL THEN GPT.attrs
                       ELSE (SELECT array_agg(g) FROM generate_series(1, C.relnatts) g)
                       END) k
                JOIN pg_attribute a
-                    ON (a.attrelid = GPT.relid AND a.attnum = k)
+                    ON (a.attrelid = GPT.relid AND a.attphysnum = k)
         ) AS attnames,
         pg_get_expr(GPT.qual, GPT.relid) AS rowfilter
     FROM pg_publication P,
@@ -446,7 +446,7 @@ FROM
     pg_seclabel l
     JOIN pg_class rel ON l.classoid = rel.tableoid AND l.objoid = rel.oid
     JOIN pg_attribute att
-         ON rel.oid = att.attrelid AND l.objsubid = att.attnum
+         ON rel.oid = att.attrelid AND l.objsubid = att.attphysnum
     JOIN pg_namespace nsp ON rel.relnamespace = nsp.oid
 WHERE
     l.objsubid != 0
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index 2da6b75a15..fe0b81d99e 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -95,7 +95,7 @@ static void compute_index_stats(Relation onerel, double totalrows,
 								AnlIndexData *indexdata, int nindexes,
 								HeapTuple *rows, int numrows,
 								MemoryContext col_context);
-static VacAttrStats *examine_attribute(Relation onerel, int attnum,
+static VacAttrStats *examine_attribute(Relation onerel, int attphysnum,
 									   Node *index_expr);
 static int	acquire_sample_rows(Relation onerel, int elevel,
 								HeapTuple *rows, int targrows,
@@ -574,7 +574,7 @@ do_analyze_rel(Relation onerel, VacuumParams *params,
 			 * If the appropriate flavor of the n_distinct option is
 			 * specified, override with the corresponding value.
 			 */
-			aopt = get_attribute_options(onerel->rd_id, stats->attr->attnum);
+			aopt = get_attribute_options(onerel->rd_id, stats->attr->attphysnum);
 			if (aopt != NULL)
 			{
 				float8		n_distinct;
@@ -928,16 +928,16 @@ compute_index_stats(Relation onerel, double totalrows,
 				for (i = 0; i < attr_cnt; i++)
 				{
 					VacAttrStats *stats = thisdata->vacattrstats[i];
-					int			attnum = stats->attr->attnum;
+					int			attphysnum = stats->attr->attphysnum;
 
-					if (isnull[attnum - 1])
+					if (isnull[attphysnum - 1])
 					{
 						exprvals[tcnt] = (Datum) 0;
 						exprnulls[tcnt] = true;
 					}
 					else
 					{
-						exprvals[tcnt] = datumCopy(values[attnum - 1],
+						exprvals[tcnt] = datumCopy(values[attphysnum - 1],
 												   stats->attrtype->typbyval,
 												   stats->attrtype->typlen);
 						exprnulls[tcnt] = false;
@@ -998,9 +998,9 @@ compute_index_stats(Relation onerel, double totalrows,
  * and index_expr is the expression tree representing the column's data.
  */
 static VacAttrStats *
-examine_attribute(Relation onerel, int attnum, Node *index_expr)
+examine_attribute(Relation onerel, int attphysnum, Node *index_expr)
 {
-	Form_pg_attribute attr = TupleDescAttr(onerel->rd_att, attnum - 1);
+	Form_pg_attribute attr = TupleDescAttr(onerel->rd_att, attphysnum - 1);
 	HeapTuple	typtuple;
 	VacAttrStats *stats;
 	int			i;
@@ -1041,8 +1041,8 @@ examine_attribute(Relation onerel, int attnum, Node *index_expr)
 		 * preference to anything else; but if not, fall back to whatever we
 		 * can get from the expression.
 		 */
-		if (OidIsValid(onerel->rd_indcollation[attnum - 1]))
-			stats->attrcollid = onerel->rd_indcollation[attnum - 1];
+		if (OidIsValid(onerel->rd_indcollation[attphysnum - 1]))
+			stats->attrcollid = onerel->rd_indcollation[attphysnum - 1];
 		else
 			stats->attrcollid = exprCollation(index_expr);
 	}
@@ -1059,7 +1059,7 @@ examine_attribute(Relation onerel, int attnum, Node *index_expr)
 		elog(ERROR, "cache lookup failed for type %u", stats->attrtypid);
 	stats->attrtype = (Form_pg_type) GETSTRUCT(typtuple);
 	stats->anl_context = anl_context;
-	stats->tupattnum = attnum;
+	stats->tupattnum = attphysnum;
 
 	/*
 	 * The fields describing the stats->stavalues[n] element types default to
@@ -1656,7 +1656,7 @@ update_attstats(Oid relid, bool inh, int natts, VacAttrStats **vacattrstats)
 		}
 
 		values[Anum_pg_statistic_starelid - 1] = ObjectIdGetDatum(relid);
-		values[Anum_pg_statistic_staattnum - 1] = Int16GetDatum(stats->attr->attnum);
+		values[Anum_pg_statistic_staattnum - 1] = Int16GetDatum(stats->attr->attphysnum);
 		values[Anum_pg_statistic_stainherit - 1] = BoolGetDatum(inh);
 		values[Anum_pg_statistic_stanullfrac - 1] = Float4GetDatum(stats->stanullfrac);
 		values[Anum_pg_statistic_stawidth - 1] = Int32GetDatum(stats->stawidth);
@@ -1725,7 +1725,7 @@ update_attstats(Oid relid, bool inh, int natts, VacAttrStats **vacattrstats)
 		/* Is there already a pg_statistic tuple for this attribute? */
 		oldtup = SearchSysCache3(STATRELATTINH,
 								 ObjectIdGetDatum(relid),
-								 Int16GetDatum(stats->attr->attnum),
+								 Int16GetDatum(stats->attr->attphysnum),
 								 BoolGetDatum(inh));
 
 		if (HeapTupleIsValid(oldtup))
@@ -1761,11 +1761,11 @@ update_attstats(Oid relid, bool inh, int natts, VacAttrStats **vacattrstats)
 static Datum
 std_fetch_func(VacAttrStatsP stats, int rownum, bool *isNull)
 {
-	int			attnum = stats->tupattnum;
+	int			attphysnum = stats->tupattnum;
 	HeapTuple	tuple = stats->rows[rownum];
 	TupleDesc	tupDesc = stats->tupDesc;
 
-	return heap_getattr(tuple, attnum, tupDesc, isNull);
+	return heap_getattr(tuple, attphysnum, tupDesc, isNull);
 }
 
 /*
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index e2870e3c11..6b15837dba 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -739,11 +739,11 @@ CopyGetAttnums(TupleDesc tupDesc, Relation rel, List *attnamelist)
 		foreach(l, attnamelist)
 		{
 			char	   *name = strVal(lfirst(l));
-			int			attnum;
+			int			attphysnum;
 			int			i;
 
 			/* Lookup column name */
-			attnum = InvalidAttrNumber;
+			attphysnum = InvalidAttrNumber;
 			for (i = 0; i < tupDesc->natts; i++)
 			{
 				Form_pg_attribute att = TupleDescAttr(tupDesc, i);
@@ -758,11 +758,11 @@ CopyGetAttnums(TupleDesc tupDesc, Relation rel, List *attnamelist)
 								 errmsg("column \"%s\" is a generated column",
 										name),
 								 errdetail("Generated columns cannot be used in COPY.")));
-					attnum = att->attnum;
+					attphysnum = att->attphysnum;
 					break;
 				}
 			}
-			if (attnum == InvalidAttrNumber)
+			if (attphysnum == InvalidAttrNumber)
 			{
 				if (rel != NULL)
 					ereport(ERROR,
@@ -776,12 +776,12 @@ CopyGetAttnums(TupleDesc tupDesc, Relation rel, List *attnamelist)
 									name)));
 			}
 			/* Check for duplicates */
-			if (list_member_int(attnums, attnum))
+			if (list_member_int(attnums, attphysnum))
 				ereport(ERROR,
 						(errcode(ERRCODE_DUPLICATE_COLUMN),
 						 errmsg("column \"%s\" specified more than once",
 								name)));
-			attnums = lappend_int(attnums, attnum);
+			attnums = lappend_int(attnums, attphysnum);
 		}
 	}
 
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
index 35a1d3a774..ca44d12b11 100644
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -1202,7 +1202,7 @@ BeginCopyFrom(ParseState *pstate,
 				num_defaults;
 	FmgrInfo   *in_functions;
 	Oid		   *typioparams;
-	int			attnum;
+	int			attphysnum;
 	Oid			in_func_oid;
 	int		   *defmap;
 	ExprState **defexprs;
@@ -1258,15 +1258,15 @@ BeginCopyFrom(ParseState *pstate,
 
 		foreach(cur, attnums)
 		{
-			int			attnum = lfirst_int(cur);
-			Form_pg_attribute attr = TupleDescAttr(tupDesc, attnum - 1);
+			int			attphysnum = lfirst_int(cur);
+			Form_pg_attribute attr = TupleDescAttr(tupDesc, attphysnum - 1);
 
-			if (!list_member_int(cstate->attnumlist, attnum))
+			if (!list_member_int(cstate->attnumlist, attphysnum))
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 						 errmsg("FORCE_NOT_NULL column \"%s\" not referenced by COPY",
 								NameStr(attr->attname))));
-			cstate->opts.force_notnull_flags[attnum - 1] = true;
+			cstate->opts.force_notnull_flags[attphysnum - 1] = true;
 		}
 	}
 
@@ -1281,15 +1281,15 @@ BeginCopyFrom(ParseState *pstate,
 
 		foreach(cur, attnums)
 		{
-			int			attnum = lfirst_int(cur);
-			Form_pg_attribute attr = TupleDescAttr(tupDesc, attnum - 1);
+			int			attphysnum = lfirst_int(cur);
+			Form_pg_attribute attr = TupleDescAttr(tupDesc, attphysnum - 1);
 
-			if (!list_member_int(cstate->attnumlist, attnum))
+			if (!list_member_int(cstate->attnumlist, attphysnum))
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 						 errmsg("FORCE_NULL column \"%s\" not referenced by COPY",
 								NameStr(attr->attname))));
-			cstate->opts.force_null_flags[attnum - 1] = true;
+			cstate->opts.force_null_flags[attphysnum - 1] = true;
 		}
 	}
 
@@ -1305,15 +1305,15 @@ BeginCopyFrom(ParseState *pstate,
 
 		foreach(cur, attnums)
 		{
-			int			attnum = lfirst_int(cur);
-			Form_pg_attribute attr = TupleDescAttr(tupDesc, attnum - 1);
+			int			attphysnum = lfirst_int(cur);
+			Form_pg_attribute attr = TupleDescAttr(tupDesc, attphysnum - 1);
 
-			if (!list_member_int(cstate->attnumlist, attnum))
+			if (!list_member_int(cstate->attnumlist, attphysnum))
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 						 errmsg_internal("selected column \"%s\" not referenced by COPY",
 										 NameStr(attr->attname))));
-			cstate->convert_select_flags[attnum - 1] = true;
+			cstate->convert_select_flags[attphysnum - 1] = true;
 		}
 	}
 
@@ -1401,9 +1401,9 @@ BeginCopyFrom(ParseState *pstate,
 	defmap = (int *) palloc(num_phys_attrs * sizeof(int));
 	defexprs = (ExprState **) palloc(num_phys_attrs * sizeof(ExprState *));
 
-	for (attnum = 1; attnum <= num_phys_attrs; attnum++)
+	for (attphysnum = 1; attphysnum <= num_phys_attrs; attphysnum++)
 	{
-		Form_pg_attribute att = TupleDescAttr(tupDesc, attnum - 1);
+		Form_pg_attribute att = TupleDescAttr(tupDesc, attphysnum - 1);
 
 		/* We don't need info for dropped attributes */
 		if (att->attisdropped)
@@ -1412,19 +1412,19 @@ BeginCopyFrom(ParseState *pstate,
 		/* Fetch the input function and typioparam info */
 		if (cstate->opts.binary)
 			getTypeBinaryInputInfo(att->atttypid,
-								   &in_func_oid, &typioparams[attnum - 1]);
+								   &in_func_oid, &typioparams[attphysnum - 1]);
 		else
 			getTypeInputInfo(att->atttypid,
-							 &in_func_oid, &typioparams[attnum - 1]);
-		fmgr_info(in_func_oid, &in_functions[attnum - 1]);
+							 &in_func_oid, &typioparams[attphysnum - 1]);
+		fmgr_info(in_func_oid, &in_functions[attphysnum - 1]);
 
 		/* Get default info if needed */
-		if (!list_member_int(cstate->attnumlist, attnum) && !att->attgenerated)
+		if (!list_member_int(cstate->attnumlist, attphysnum) && !att->attgenerated)
 		{
 			/* attribute is NOT to be copied from input */
 			/* use default value if one exists */
 			Expr	   *defexpr = (Expr *) build_column_default(cstate->rel,
-																attnum);
+																attphysnum);
 
 			if (defexpr != NULL)
 			{
@@ -1433,7 +1433,7 @@ BeginCopyFrom(ParseState *pstate,
 
 				/* Initialize executable expression in copycontext */
 				defexprs[num_defaults] = ExecInitExpr(defexpr, NULL);
-				defmap[num_defaults] = attnum - 1;
+				defmap[num_defaults] = attphysnum - 1;
 				num_defaults++;
 
 				/*
diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 57813b3458..e9b0b294e9 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -788,9 +788,9 @@ NextCopyFromRawFields(CopyFromState cstate, char ***fields, int *nfields)
 			fldnum = 0;
 			foreach(cur, cstate->attnumlist)
 			{
-				int			attnum = lfirst_int(cur);
+				int			attphysnum = lfirst_int(cur);
 				char	   *colName;
-				Form_pg_attribute attr = TupleDescAttr(tupDesc, attnum - 1);
+				Form_pg_attribute attr = TupleDescAttr(tupDesc, attphysnum - 1);
 
 				Assert(fldnum < cstate->max_fields);
 
@@ -894,8 +894,8 @@ NextCopyFrom(CopyFromState cstate, ExprContext *econtext,
 		/* Loop to read the user attributes on the line. */
 		foreach(cur, cstate->attnumlist)
 		{
-			int			attnum = lfirst_int(cur);
-			int			m = attnum - 1;
+			int			attphysnum = lfirst_int(cur);
+			int			m = attphysnum - 1;
 			Form_pg_attribute att = TupleDescAttr(tupDesc, m);
 
 			if (fieldno >= fldct)
@@ -991,8 +991,8 @@ NextCopyFrom(CopyFromState cstate, ExprContext *econtext,
 
 		foreach(cur, cstate->attnumlist)
 		{
-			int			attnum = lfirst_int(cur);
-			int			m = attnum - 1;
+			int			attphysnum = lfirst_int(cur);
+			int			m = attphysnum - 1;
 			Form_pg_attribute att = TupleDescAttr(tupDesc, m);
 
 			cstate->cur_attname = NameStr(att->attname);
diff --git a/src/backend/commands/copyto.c b/src/backend/commands/copyto.c
index fca29a9a10..e0306cc11b 100644
--- a/src/backend/commands/copyto.c
+++ b/src/backend/commands/copyto.c
@@ -579,15 +579,15 @@ BeginCopyTo(ParseState *pstate,
 
 		foreach(cur, attnums)
 		{
-			int			attnum = lfirst_int(cur);
-			Form_pg_attribute attr = TupleDescAttr(tupDesc, attnum - 1);
+			int			attphysnum = lfirst_int(cur);
+			Form_pg_attribute attr = TupleDescAttr(tupDesc, attphysnum - 1);
 
-			if (!list_member_int(cstate->attnumlist, attnum))
+			if (!list_member_int(cstate->attnumlist, attphysnum))
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 						 errmsg("FORCE_QUOTE column \"%s\" not referenced by COPY",
 								NameStr(attr->attname))));
-			cstate->opts.force_quote_flags[attnum - 1] = true;
+			cstate->opts.force_quote_flags[attphysnum - 1] = true;
 		}
 	}
 
@@ -602,15 +602,15 @@ BeginCopyTo(ParseState *pstate,
 
 		foreach(cur, attnums)
 		{
-			int			attnum = lfirst_int(cur);
-			Form_pg_attribute attr = TupleDescAttr(tupDesc, attnum - 1);
+			int			attphysnum = lfirst_int(cur);
+			Form_pg_attribute attr = TupleDescAttr(tupDesc, attphysnum - 1);
 
-			if (!list_member_int(cstate->attnumlist, attnum))
+			if (!list_member_int(cstate->attnumlist, attphysnum))
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 						 errmsg("FORCE_NOT_NULL column \"%s\" not referenced by COPY",
 								NameStr(attr->attname))));
-			cstate->opts.force_notnull_flags[attnum - 1] = true;
+			cstate->opts.force_notnull_flags[attphysnum - 1] = true;
 		}
 	}
 
@@ -625,15 +625,15 @@ BeginCopyTo(ParseState *pstate,
 
 		foreach(cur, attnums)
 		{
-			int			attnum = lfirst_int(cur);
-			Form_pg_attribute attr = TupleDescAttr(tupDesc, attnum - 1);
+			int			attphysnum = lfirst_int(cur);
+			Form_pg_attribute attr = TupleDescAttr(tupDesc, attphysnum - 1);
 
-			if (!list_member_int(cstate->attnumlist, attnum))
+			if (!list_member_int(cstate->attnumlist, attphysnum))
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 						 errmsg("FORCE_NULL column \"%s\" not referenced by COPY",
 								NameStr(attr->attname))));
-			cstate->opts.force_null_flags[attnum - 1] = true;
+			cstate->opts.force_null_flags[attphysnum - 1] = true;
 		}
 	}
 
@@ -793,10 +793,10 @@ DoCopyTo(CopyToState cstate)
 	cstate->out_functions = (FmgrInfo *) palloc(num_phys_attrs * sizeof(FmgrInfo));
 	foreach(cur, cstate->attnumlist)
 	{
-		int			attnum = lfirst_int(cur);
+		int			attphysnum = lfirst_int(cur);
 		Oid			out_func_oid;
 		bool		isvarlena;
-		Form_pg_attribute attr = TupleDescAttr(tupDesc, attnum - 1);
+		Form_pg_attribute attr = TupleDescAttr(tupDesc, attphysnum - 1);
 
 		if (cstate->opts.binary)
 			getTypeBinaryOutputInfo(attr->atttypid,
@@ -806,7 +806,7 @@ DoCopyTo(CopyToState cstate)
 			getTypeOutputInfo(attr->atttypid,
 							  &out_func_oid,
 							  &isvarlena);
-		fmgr_info(out_func_oid, &cstate->out_functions[attnum - 1]);
+		fmgr_info(out_func_oid, &cstate->out_functions[attphysnum - 1]);
 	}
 
 	/*
@@ -851,14 +851,14 @@ DoCopyTo(CopyToState cstate)
 
 			foreach(cur, cstate->attnumlist)
 			{
-				int			attnum = lfirst_int(cur);
+				int			attphysnum = lfirst_int(cur);
 				char	   *colname;
 
 				if (hdr_delim)
 					CopySendChar(cstate, cstate->opts.delim[0]);
 				hdr_delim = true;
 
-				colname = NameStr(TupleDescAttr(tupDesc, attnum - 1)->attname);
+				colname = NameStr(TupleDescAttr(tupDesc, attphysnum - 1)->attname);
 
 				if (cstate->opts.csv_mode)
 					CopyAttributeOutCSV(cstate, colname, false,
@@ -950,9 +950,9 @@ CopyOneRowTo(CopyToState cstate, TupleTableSlot *slot)
 
 	foreach(cur, cstate->attnumlist)
 	{
-		int			attnum = lfirst_int(cur);
-		Datum		value = slot->tts_values[attnum - 1];
-		bool		isnull = slot->tts_isnull[attnum - 1];
+		int			attphysnum = lfirst_int(cur);
+		Datum		value = slot->tts_values[attphysnum - 1];
+		bool		isnull = slot->tts_isnull[attphysnum - 1];
 
 		if (!cstate->opts.binary)
 		{
@@ -972,11 +972,11 @@ CopyOneRowTo(CopyToState cstate, TupleTableSlot *slot)
 		{
 			if (!cstate->opts.binary)
 			{
-				string = OutputFunctionCall(&out_functions[attnum - 1],
+				string = OutputFunctionCall(&out_functions[attphysnum - 1],
 											value);
 				if (cstate->opts.csv_mode)
 					CopyAttributeOutCSV(cstate, string,
-										cstate->opts.force_quote_flags[attnum - 1],
+										cstate->opts.force_quote_flags[attphysnum - 1],
 										list_length(cstate->attnumlist) == 1);
 				else
 					CopyAttributeOutText(cstate, string);
@@ -985,7 +985,7 @@ CopyOneRowTo(CopyToState cstate, TupleTableSlot *slot)
 			{
 				bytea	   *outputbytes;
 
-				outputbytes = SendFunctionCall(&out_functions[attnum - 1],
+				outputbytes = SendFunctionCall(&out_functions[attphysnum - 1],
 											   value);
 				CopySendInt32(cstate, VARSIZE(outputbytes) - VARHDRSZ);
 				CopySendData(cstate, VARDATA(outputbytes),
diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c
index 9abbb6b555..ec046d77cf 100644
--- a/src/backend/commands/createas.c
+++ b/src/backend/commands/createas.c
@@ -453,7 +453,7 @@ intorel_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
 	ObjectAddress intoRelationAddr;
 	Relation	intoRelationDesc;
 	ListCell   *lc;
-	int			attnum;
+	int			attphysnum;
 
 	Assert(into != NULL);		/* else somebody forgot to set it */
 
@@ -468,9 +468,9 @@ intorel_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
 	 */
 	attrList = NIL;
 	lc = list_head(into->colNames);
-	for (attnum = 0; attnum < typeinfo->natts; attnum++)
+	for (attphysnum = 0; attphysnum < typeinfo->natts; attphysnum++)
 	{
-		Form_pg_attribute attribute = TupleDescAttr(typeinfo, attnum);
+		Form_pg_attribute attribute = TupleDescAttr(typeinfo, attphysnum);
 		ColumnDef  *col;
 		char	   *colname;
 
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index 4642527881..2b3dbfbcb1 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -1211,14 +1211,14 @@ EventTriggerSQLDropAddObject(const ObjectAddress *object, bool original, bool no
 
 		if (tuple)
 		{
-			AttrNumber	attnum;
+			AttrNumber	attphysnum;
 			Datum		datum;
 			bool		isnull;
 
-			attnum = get_object_attnum_namespace(obj->address.classId);
-			if (attnum != InvalidAttrNumber)
+			attphysnum = get_object_attnum_namespace(obj->address.classId);
+			if (attphysnum != InvalidAttrNumber)
 			{
-				datum = heap_getattr(tuple, attnum,
+				datum = heap_getattr(tuple, attphysnum,
 									 RelationGetDescr(catalog), &isnull);
 				if (!isnull)
 				{
@@ -1249,10 +1249,10 @@ EventTriggerSQLDropAddObject(const ObjectAddress *object, bool original, bool no
 			if (get_object_namensp_unique(obj->address.classId) &&
 				obj->address.objectSubId == 0)
 			{
-				attnum = get_object_attnum_name(obj->address.classId);
-				if (attnum != InvalidAttrNumber)
+				attphysnum = get_object_attnum_name(obj->address.classId);
+				if (attphysnum != InvalidAttrNumber)
 				{
-					datum = heap_getattr(tuple, attnum,
+					datum = heap_getattr(tuple, attphysnum,
 										 RelationGetDescr(catalog), &isnull);
 					if (!isnull)
 						obj->objname = pstrdup(NameStr(*DatumGetName(datum)));
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 99f5ab83c3..4460201217 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -1823,7 +1823,7 @@ ComputeIndexAttrs(IndexInfo *indexInfo,
 									attribute->name)));
 			}
 			attform = (Form_pg_attribute) GETSTRUCT(atttuple);
-			indexInfo->ii_IndexAttrNumbers[attn] = attform->attnum;
+			indexInfo->ii_IndexAttrNumbers[attn] = attform->attphysnum;
 			atttype = attform->atttypid;
 			attcollation = attform->attcollation;
 			ReleaseSysCache(atttuple);
diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index d1ee106465..47ea6f6246 100644
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -705,9 +705,9 @@ refresh_by_match_merge(Oid matviewOid, Oid tempOid, Oid relowner,
 			/* Add quals for all columns from this index. */
 			for (i = 0; i < indnkeyatts; i++)
 			{
-				int			attnum = indexStruct->indkey.values[i];
+				int			attphysnum = indexStruct->indkey.values[i];
 				Oid			opclass = indclass->values[i];
-				Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
+				Form_pg_attribute attr = TupleDescAttr(tupdesc, attphysnum - 1);
 				Oid			attrtype = attr->atttypid;
 				HeapTuple	cla_ht;
 				Form_pg_opclass cla_tup;
@@ -747,9 +747,9 @@ refresh_by_match_merge(Oid matviewOid, Oid tempOid, Oid relowner,
 				 * that's so unlikely it doesn't seem worth spending extra
 				 * code to avoid.
 				 */
-				if (opUsedForQual[attnum - 1] == op)
+				if (opUsedForQual[attphysnum - 1] == op)
 					continue;
-				opUsedForQual[attnum - 1] = op;
+				opUsedForQual[attphysnum - 1] = op;
 
 				/*
 				 * Actually add the qual, ANDed with any others.
@@ -894,9 +894,9 @@ is_usable_unique_index(Relation indexRel)
 
 		for (i = 0; i < numatts; i++)
 		{
-			int			attnum = indexStruct->indkey.values[i];
+			int			attphysnum = indexStruct->indkey.values[i];
 
-			if (attnum <= 0)
+			if (attphysnum <= 0)
 				return false;
 		}
 		return true;
diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 8e645741e4..4a4c6ffac5 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -265,7 +265,7 @@ contain_invalid_rfcolumn_walker(Node *node, rf_context *context)
 	if (IsA(node, Var))
 	{
 		Var		   *var = (Var *) node;
-		AttrNumber	attnum = var->varattno;
+		AttrNumber	attphysnum = var->varattno;
 
 		/*
 		 * If pubviaroot is true, we are validating the row filter of the
@@ -275,12 +275,12 @@ contain_invalid_rfcolumn_walker(Node *node, rf_context *context)
 		 */
 		if (context->pubviaroot)
 		{
-			char	   *colname = get_attname(context->parentid, attnum, false);
+			char	   *colname = get_attname(context->parentid, attphysnum, false);
 
-			attnum = get_attnum(context->relid, colname);
+			attphysnum = get_attphysnum(context->relid, colname);
 		}
 
-		if (!bms_is_member(attnum - FirstLowInvalidHeapAttributeNumber,
+		if (!bms_is_member(attphysnum - FirstLowInvalidHeapAttributeNumber,
 						   context->bms_replident))
 			return true;
 	}
@@ -436,7 +436,7 @@ pub_collist_contains_invalid_column(Oid pubid, Relation relation, List *ancestor
 		x = -1;
 		while ((x = bms_next_member(idattrs, x)) >= 0)
 		{
-			AttrNumber	attnum = (x + FirstLowInvalidHeapAttributeNumber);
+			AttrNumber	attphysnum = (x + FirstLowInvalidHeapAttributeNumber);
 
 			/*
 			 * If pubviaroot is true, we are validating the column list of the
@@ -448,17 +448,17 @@ pub_collist_contains_invalid_column(Oid pubid, Relation relation, List *ancestor
 			if (pubviaroot)
 			{
 				/* attribute name in the child table */
-				char	   *colname = get_attname(relid, attnum, false);
+				char	   *colname = get_attname(relid, attphysnum, false);
 
 				/*
-				 * Determine the attnum for the attribute name in parent (we
+				 * Determine the attphysnum for the attribute name in parent (we
 				 * are using the column list defined on the parent).
 				 */
-				attnum = get_attnum(publish_as_relid, colname);
+				attphysnum = get_attphysnum(publish_as_relid, colname);
 			}
 
 			/* replica identity column, not covered by the column list */
-			if (!bms_is_member(attnum, columns))
+			if (!bms_is_member(attphysnum, columns))
 			{
 				result = true;
 				break;
@@ -1228,9 +1228,9 @@ AlterPublicationTables(AlterPublicationStmt *stmt, HeapTuple tup,
 					foreach(lc, newpubrel->columns)
 					{
 						char	   *colname = strVal(lfirst(lc));
-						AttrNumber	attnum = get_attnum(newrelid, colname);
+						AttrNumber	attphysnum = get_attphysnum(newrelid, colname);
 
-						newcolumns = bms_add_member(newcolumns, attnum);
+						newcolumns = bms_add_member(newcolumns, attphysnum);
 					}
 				}
 
diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index ddf219b21f..0fb47c6d81 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -1595,7 +1595,7 @@ process_owned_by(Relation seqrel, List *owned_by, bool for_identity)
 	DependencyType deptype;
 	int			nnames;
 	Relation	tablerel;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 
 	deptype = for_identity ? DEPENDENCY_INTERNAL : DEPENDENCY_AUTO;
 
@@ -1610,7 +1610,7 @@ process_owned_by(Relation seqrel, List *owned_by, bool for_identity)
 					 errmsg("invalid OWNED BY option"),
 					 errhint("Specify OWNED BY table.column or OWNED BY NONE.")));
 		tablerel = NULL;
-		attnum = 0;
+		attphysnum = 0;
 	}
 	else
 	{
@@ -1648,8 +1648,8 @@ process_owned_by(Relation seqrel, List *owned_by, bool for_identity)
 					 errmsg("sequence must be in same schema as table it is linked to")));
 
 		/* Now, fetch the attribute number from the system cache */
-		attnum = get_attnum(RelationGetRelid(tablerel), attrname);
-		if (attnum == InvalidAttrNumber)
+		attphysnum = get_attphysnum(RelationGetRelid(tablerel), attrname);
+		if (attphysnum == InvalidAttrNumber)
 			ereport(ERROR,
 					(errcode(ERRCODE_UNDEFINED_COLUMN),
 					 errmsg("column \"%s\" of relation \"%s\" does not exist",
@@ -1687,7 +1687,7 @@ process_owned_by(Relation seqrel, List *owned_by, bool for_identity)
 
 		refobject.classId = RelationRelationId;
 		refobject.objectId = RelationGetRelid(tablerel);
-		refobject.objectSubId = attnum;
+		refobject.objectSubId = attphysnum;
 		depobject.classId = RelationRelationId;
 		depobject.objectId = RelationGetRelid(seqrel);
 		depobject.objectSubId = 0;
diff --git a/src/backend/commands/statscmds.c b/src/backend/commands/statscmds.c
index 2e716743dd..737ee30e64 100644
--- a/src/backend/commands/statscmds.c
+++ b/src/backend/commands/statscmds.c
@@ -241,7 +241,7 @@ CreateStatistics(CreateStatsStmt *stmt)
 			attForm = (Form_pg_attribute) GETSTRUCT(atttuple);
 
 			/* Disallow use of system attributes in extended stats */
-			if (attForm->attnum <= 0)
+			if (attForm->attphysnum <= 0)
 				ereport(ERROR,
 						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 						 errmsg("statistics creation on system columns is not supported")));
@@ -254,7 +254,7 @@ CreateStatistics(CreateStatsStmt *stmt)
 						 errmsg("column \"%s\" cannot be used in statistics because its type %s has no default btree operator class",
 								attname, format_type_be(attForm->atttypid))));
 
-			attnums[nattnums] = attForm->attnum;
+			attnums[nattnums] = attForm->attphysnum;
 			nattnums++;
 			ReleaseSysCache(atttuple);
 		}
@@ -296,9 +296,9 @@ CreateStatistics(CreateStatsStmt *stmt)
 			k = -1;
 			while ((k = bms_next_member(attnums, k)) >= 0)
 			{
-				AttrNumber	attnum = k + FirstLowInvalidHeapAttributeNumber;
+				AttrNumber	attphysnum = k + FirstLowInvalidHeapAttributeNumber;
 
-				if (attnum <= 0)
+				if (attphysnum <= 0)
 					ereport(ERROR,
 							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 							 errmsg("statistics creation on system columns is not supported")));
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 2de0ebacec..ff9a9fc911 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -219,7 +219,7 @@ typedef struct NewConstraint
  */
 typedef struct NewColumnValue
 {
-	AttrNumber	attnum;			/* which column */
+	AttrNumber	attphysnum;			/* which column */
 	Expr	   *expr;			/* expression to compute */
 	ExprState  *exprstate;		/* execution state */
 	bool		is_generated;	/* is it a GENERATED expression? */
@@ -427,8 +427,8 @@ static ObjectAddress ATExecAddColumn(List **wqueue, AlteredTableInfo *tab,
 									 AlterTableUtilityContext *context);
 static bool check_for_column_name_collision(Relation rel, const char *colname,
 											bool if_not_exists);
-static void add_column_datatype_dependency(Oid relid, int32 attnum, Oid typid);
-static void add_column_collation_dependency(Oid relid, int32 attnum, Oid collid);
+static void add_column_datatype_dependency(Oid relid, int32 attphysnum, Oid typid);
+static void add_column_collation_dependency(Oid relid, int32 attphysnum, Oid collid);
 static void ATPrepDropNotNull(Relation rel, bool recurse, bool recursing);
 static ObjectAddress ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode);
 static void ATPrepSetNotNull(List **wqueue, Relation rel,
@@ -444,7 +444,7 @@ static bool ConstraintImpliedByRelConstraint(Relation scanrel,
 											 List *testConstraint, List *provenConstraint);
 static ObjectAddress ATExecColumnDefault(Relation rel, const char *colName,
 										 Node *newDefault, LOCKMODE lockmode);
-static ObjectAddress ATExecCookedColumnDefault(Relation rel, AttrNumber attnum,
+static ObjectAddress ATExecCookedColumnDefault(Relation rel, AttrNumber attphysnum,
 											   Node *newDefault);
 static ObjectAddress ATExecAddIdentity(Relation rel, const char *colName,
 									   Node *def, LOCKMODE lockmode);
@@ -670,7 +670,7 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 	List	   *cookedDefaults;
 	Datum		reloptions;
 	ListCell   *listptr;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	bool		partitioned;
 	static char *validnsps[] = HEAP_RELOPT_NAMESPACES;
 	Oid			ofTypeId;
@@ -880,15 +880,15 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 	 */
 	rawDefaults = NIL;
 	cookedDefaults = NIL;
-	attnum = 0;
+	attphysnum = 0;
 
 	foreach(listptr, stmt->tableElts)
 	{
 		ColumnDef  *colDef = lfirst(listptr);
 		Form_pg_attribute attr;
 
-		attnum++;
-		attr = TupleDescAttr(descriptor, attnum - 1);
+		attphysnum++;
+		attr = TupleDescAttr(descriptor, attphysnum - 1);
 
 		if (colDef->raw_default != NULL)
 		{
@@ -897,7 +897,7 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 			Assert(colDef->cooked_default == NULL);
 
 			rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault));
-			rawEnt->attnum = attnum;
+			rawEnt->attphysnum = attphysnum;
 			rawEnt->raw_default = colDef->raw_default;
 			rawEnt->missingMode = false;
 			rawEnt->generated = colDef->generated;
@@ -912,7 +912,7 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 			cooked->contype = CONSTR_DEFAULT;
 			cooked->conoid = InvalidOid;	/* until created */
 			cooked->name = NULL;
-			cooked->attnum = attnum;
+			cooked->attphysnum = attphysnum;
 			cooked->expr = colDef->cooked_default;
 			cooked->skip_validation = false;
 			cooked->is_local = true;	/* not used for defaults */
@@ -2774,7 +2774,7 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
 					cooked->contype = CONSTR_CHECK;
 					cooked->conoid = InvalidOid;	/* until created */
 					cooked->name = pstrdup(name);
-					cooked->attnum = 0; /* not used for constraints */
+					cooked->attphysnum = 0; /* not used for constraints */
 					cooked->expr = expr;
 					cooked->skip_validation = false;
 					cooked->is_local = false;
@@ -3432,7 +3432,7 @@ renameatt_internal(Oid myrelid,
 	Relation	attrelation;
 	HeapTuple	atttup;
 	Form_pg_attribute attform;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 
 	/*
 	 * Grab an exclusive lock on the target table, which we will NOT release
@@ -3520,8 +3520,8 @@ renameatt_internal(Oid myrelid,
 						oldattname)));
 	attform = (Form_pg_attribute) GETSTRUCT(atttup);
 
-	attnum = attform->attnum;
-	if (attnum <= 0)
+	attphysnum = attform->attphysnum;
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot rename system column \"%s\"",
@@ -3550,7 +3550,7 @@ renameatt_internal(Oid myrelid,
 
 	CatalogTupleUpdate(attrelation, &atttup->t_self, atttup);
 
-	InvokeObjectPostAlterHook(RelationRelationId, myrelid, attnum);
+	InvokeObjectPostAlterHook(RelationRelationId, myrelid, attphysnum);
 
 	heap_freetuple(atttup);
 
@@ -3558,7 +3558,7 @@ renameatt_internal(Oid myrelid,
 
 	relation_close(targetrelation, NoLock); /* close rel but keep lock */
 
-	return attnum;
+	return attphysnum;
 }
 
 /*
@@ -3588,7 +3588,7 @@ ObjectAddress
 renameatt(RenameStmt *stmt)
 {
 	Oid			relid;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	ObjectAddress address;
 
 	/* lock level taken here should match renameatt_internal */
@@ -3605,7 +3605,7 @@ renameatt(RenameStmt *stmt)
 		return InvalidObjectAddress;
 	}
 
-	attnum =
+	attphysnum =
 		renameatt_internal(relid,
 						   stmt->subname,	/* old att name */
 						   stmt->newname,	/* new att name */
@@ -3614,7 +3614,7 @@ renameatt(RenameStmt *stmt)
 						   0,	/* expected inhcount */
 						   stmt->behavior);
 
-	ObjectAddressSubSet(address, RelationRelationId, relid, attnum);
+	ObjectAddressSubSet(address, RelationRelationId, relid, attphysnum);
 
 	return address;
 }
@@ -5899,10 +5899,10 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
 					if (ex->is_generated)
 						continue;
 
-					newslot->tts_values[ex->attnum - 1]
+					newslot->tts_values[ex->attphysnum - 1]
 						= ExecEvalExpr(ex->exprstate,
 									   econtext,
-									   &newslot->tts_isnull[ex->attnum - 1]);
+									   &newslot->tts_isnull[ex->attphysnum - 1]);
 				}
 
 				ExecStoreVirtualTuple(newslot);
@@ -5921,10 +5921,10 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
 					if (!ex->is_generated)
 						continue;
 
-					newslot->tts_values[ex->attnum - 1]
+					newslot->tts_values[ex->attphysnum - 1]
 						= ExecEvalExpr(ex->exprstate,
 									   econtext,
-									   &newslot->tts_isnull[ex->attnum - 1]);
+									   &newslot->tts_isnull[ex->attphysnum - 1]);
 				}
 
 				insertslot = newslot;
@@ -6814,7 +6814,7 @@ ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	attribute.atttypid = typeOid;
 	attribute.attstattarget = (newattnum > 0) ? -1 : 0;
 	attribute.attlen = tform->typlen;
-	attribute.attnum = newattnum;
+	attribute.attphysnum = newattnum;
 	attribute.attndims = list_length(colDef->typeName->arrayBounds);
 	attribute.atttypmod = typmod;
 	attribute.attbyval = tform->typbyval;
@@ -6865,7 +6865,7 @@ ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
 		RawColumnDefault *rawEnt;
 
 		rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault));
-		rawEnt->attnum = attribute.attnum;
+		rawEnt->attphysnum = attribute.attphysnum;
 		rawEnt->raw_default = copyObject(colDef->raw_default);
 
 		/*
@@ -6900,7 +6900,7 @@ ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	 *
 	 * If there is no default, Phase 3 doesn't have to do anything, because
 	 * that effectively means that the default is NULL.  The heap tuple access
-	 * routines always check for attnum > # of attributes in tuple, and return
+	 * routines always check for attphysnum > # of attributes in tuple, and return
 	 * NULL if so, so without any modification of the tuple data we will get
 	 * the effect of NULL values in the new column.
 	 *
@@ -6928,7 +6928,7 @@ ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	 * is certainly not going to touch them.  System attributes don't have
 	 * interesting defaults, either.
 	 */
-	if (RELKIND_HAS_STORAGE(relkind) && attribute.attnum > 0)
+	if (RELKIND_HAS_STORAGE(relkind) && attribute.attphysnum > 0)
 	{
 		/*
 		 * For an identity column, we can't use build_column_default(),
@@ -6947,7 +6947,7 @@ ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
 			tab->rewrite |= AT_REWRITE_DEFAULT_VAL;
 		}
 		else
-			defval = (Expr *) build_column_default(rel, attribute.attnum);
+			defval = (Expr *) build_column_default(rel, attribute.attphysnum);
 
 		if (!defval && DomainHasConstraints(typeOid))
 		{
@@ -6976,7 +6976,7 @@ ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
 			NewColumnValue *newval;
 
 			newval = (NewColumnValue *) palloc0(sizeof(NewColumnValue));
-			newval->attnum = attribute.attnum;
+			newval->attphysnum = attribute.attphysnum;
 			newval->expr = expression_planner(defval);
 			newval->is_generated = (colDef->generated != '\0');
 
@@ -6986,7 +6986,7 @@ ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
 		if (DomainHasConstraints(typeOid))
 			tab->rewrite |= AT_REWRITE_DEFAULT_VAL;
 
-		if (!TupleDescAttr(rel->rd_att, attribute.attnum - 1)->atthasmissing)
+		if (!TupleDescAttr(rel->rd_att, attribute.attphysnum - 1)->atthasmissing)
 		{
 			/*
 			 * If the new column is NOT NULL, and there is no missing value,
@@ -7064,7 +7064,7 @@ check_for_column_name_collision(Relation rel, const char *colname,
 								bool if_not_exists)
 {
 	HeapTuple	attTuple;
-	int			attnum;
+	int			attphysnum;
 
 	/*
 	 * this test is deliberately not attisdropped-aware, since if one tries to
@@ -7076,7 +7076,7 @@ check_for_column_name_collision(Relation rel, const char *colname,
 	if (!HeapTupleIsValid(attTuple))
 		return true;
 
-	attnum = ((Form_pg_attribute) GETSTRUCT(attTuple))->attnum;
+	attphysnum = ((Form_pg_attribute) GETSTRUCT(attTuple))->attphysnum;
 	ReleaseSysCache(attTuple);
 
 	/*
@@ -7084,7 +7084,7 @@ check_for_column_name_collision(Relation rel, const char *colname,
 	 * names, since they are normally not shown and the user might otherwise
 	 * be confused about the reason for the conflict.
 	 */
-	if (attnum <= 0)
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_DUPLICATE_COLUMN),
 				 errmsg("column name \"%s\" conflicts with a system column name",
@@ -7113,14 +7113,14 @@ check_for_column_name_collision(Relation rel, const char *colname,
  * Install a column's dependency on its datatype.
  */
 static void
-add_column_datatype_dependency(Oid relid, int32 attnum, Oid typid)
+add_column_datatype_dependency(Oid relid, int32 attphysnum, Oid typid)
 {
 	ObjectAddress myself,
 				referenced;
 
 	myself.classId = RelationRelationId;
 	myself.objectId = relid;
-	myself.objectSubId = attnum;
+	myself.objectSubId = attphysnum;
 	referenced.classId = TypeRelationId;
 	referenced.objectId = typid;
 	referenced.objectSubId = 0;
@@ -7131,7 +7131,7 @@ add_column_datatype_dependency(Oid relid, int32 attnum, Oid typid)
  * Install a column's dependency on its collation.
  */
 static void
-add_column_collation_dependency(Oid relid, int32 attnum, Oid collid)
+add_column_collation_dependency(Oid relid, int32 attphysnum, Oid collid)
 {
 	ObjectAddress myself,
 				referenced;
@@ -7141,7 +7141,7 @@ add_column_collation_dependency(Oid relid, int32 attnum, Oid collid)
 	{
 		myself.classId = RelationRelationId;
 		myself.objectId = relid;
-		myself.objectSubId = attnum;
+		myself.objectSubId = attphysnum;
 		referenced.classId = CollationRelationId;
 		referenced.objectId = collid;
 		referenced.objectSubId = 0;
@@ -7182,7 +7182,7 @@ ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode)
 {
 	HeapTuple	tuple;
 	Form_pg_attribute attTup;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	Relation	attr_rel;
 	List	   *indexoidlist;
 	ListCell   *indexoidscan;
@@ -7200,10 +7200,10 @@ ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode)
 				 errmsg("column \"%s\" of relation \"%s\" does not exist",
 						colName, RelationGetRelationName(rel))));
 	attTup = (Form_pg_attribute) GETSTRUCT(tuple);
-	attnum = attTup->attnum;
+	attphysnum = attTup->attphysnum;
 
 	/* Prevent them from altering a system attribute */
-	if (attnum <= 0)
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot alter system column \"%s\"",
@@ -7250,7 +7250,7 @@ ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode)
 			 */
 			for (i = 0; i < indexStruct->indnkeyatts; i++)
 			{
-				if (indexStruct->indkey.values[i] == attnum)
+				if (indexStruct->indkey.values[i] == attphysnum)
 				{
 					if (indexStruct->indisprimary)
 						ereport(ERROR,
@@ -7279,7 +7279,7 @@ ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode)
 		TupleDesc	tupDesc = RelationGetDescr(parent);
 		AttrNumber	parent_attnum;
 
-		parent_attnum = get_attnum(parentId, colName);
+		parent_attnum = get_attphysnum(parentId, colName);
 		if (TupleDescAttr(tupDesc, parent_attnum - 1)->attnotnull)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
@@ -7298,13 +7298,13 @@ ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode)
 		CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple);
 
 		ObjectAddressSubSet(address, RelationRelationId,
-							RelationGetRelid(rel), attnum);
+							RelationGetRelid(rel), attphysnum);
 	}
 	else
 		address = InvalidObjectAddress;
 
 	InvokeObjectPostAlterHook(RelationRelationId,
-							  RelationGetRelid(rel), attnum);
+							  RelationGetRelid(rel), attphysnum);
 
 	table_close(attr_rel, RowExclusiveLock);
 
@@ -7389,7 +7389,7 @@ ATExecSetNotNull(AlteredTableInfo *tab, Relation rel,
 				 const char *colName, LOCKMODE lockmode)
 {
 	HeapTuple	tuple;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	Relation	attr_rel;
 	ObjectAddress address;
 
@@ -7406,10 +7406,10 @@ ATExecSetNotNull(AlteredTableInfo *tab, Relation rel,
 				 errmsg("column \"%s\" of relation \"%s\" does not exist",
 						colName, RelationGetRelationName(rel))));
 
-	attnum = ((Form_pg_attribute) GETSTRUCT(tuple))->attnum;
+	attphysnum = ((Form_pg_attribute) GETSTRUCT(tuple))->attphysnum;
 
 	/* Prevent them from altering a system attribute */
-	if (attnum <= 0)
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot alter system column \"%s\"",
@@ -7438,13 +7438,13 @@ ATExecSetNotNull(AlteredTableInfo *tab, Relation rel,
 		}
 
 		ObjectAddressSubSet(address, RelationRelationId,
-							RelationGetRelid(rel), attnum);
+							RelationGetRelid(rel), attphysnum);
 	}
 	else
 		address = InvalidObjectAddress;
 
 	InvokeObjectPostAlterHook(RelationRelationId,
-							  RelationGetRelid(rel), attnum);
+							  RelationGetRelid(rel), attphysnum);
 
 	table_close(attr_rel, RowExclusiveLock);
 
@@ -7501,7 +7501,7 @@ NotNullImpliedByRelConstraints(Relation rel, Form_pg_attribute attr)
 	NullTest   *nnulltest = makeNode(NullTest);
 
 	nnulltest->arg = (Expr *) makeVar(1,
-									  attr->attnum,
+									  attr->attphysnum,
 									  attr->atttypid,
 									  attr->atttypmod,
 									  attr->attcollation,
@@ -7537,39 +7537,39 @@ ATExecColumnDefault(Relation rel, const char *colName,
 					Node *newDefault, LOCKMODE lockmode)
 {
 	TupleDesc	tupdesc = RelationGetDescr(rel);
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	ObjectAddress address;
 
 	/*
 	 * get the number of the attribute
 	 */
-	attnum = get_attnum(RelationGetRelid(rel), colName);
-	if (attnum == InvalidAttrNumber)
+	attphysnum = get_attphysnum(RelationGetRelid(rel), colName);
+	if (attphysnum == InvalidAttrNumber)
 		ereport(ERROR,
 				(errcode(ERRCODE_UNDEFINED_COLUMN),
 				 errmsg("column \"%s\" of relation \"%s\" does not exist",
 						colName, RelationGetRelationName(rel))));
 
 	/* Prevent them from altering a system attribute */
-	if (attnum <= 0)
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot alter system column \"%s\"",
 						colName)));
 
-	if (TupleDescAttr(tupdesc, attnum - 1)->attidentity)
+	if (TupleDescAttr(tupdesc, attphysnum - 1)->attidentity)
 		ereport(ERROR,
 				(errcode(ERRCODE_SYNTAX_ERROR),
 				 errmsg("column \"%s\" of relation \"%s\" is an identity column",
 						colName, RelationGetRelationName(rel)),
 				 newDefault ? 0 : errhint("Use ALTER TABLE ... ALTER COLUMN ... DROP IDENTITY instead.")));
 
-	if (TupleDescAttr(tupdesc, attnum - 1)->attgenerated)
+	if (TupleDescAttr(tupdesc, attphysnum - 1)->attgenerated)
 		ereport(ERROR,
 				(errcode(ERRCODE_SYNTAX_ERROR),
 				 errmsg("column \"%s\" of relation \"%s\" is a generated column",
 						colName, RelationGetRelationName(rel)),
-				 newDefault || TupleDescAttr(tupdesc, attnum - 1)->attgenerated != ATTRIBUTE_GENERATED_STORED ? 0 :
+				 newDefault || TupleDescAttr(tupdesc, attphysnum - 1)->attgenerated != ATTRIBUTE_GENERATED_STORED ? 0 :
 				 errhint("Use ALTER TABLE ... ALTER COLUMN ... DROP EXPRESSION instead.")));
 
 	/*
@@ -7581,7 +7581,7 @@ ATExecColumnDefault(Relation rel, const char *colName,
 	 * is preparatory to adding a new default, but as a user-initiated
 	 * operation when the user asked for a drop.
 	 */
-	RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, false,
+	RemoveAttrDefault(RelationGetRelid(rel), attphysnum, DROP_RESTRICT, false,
 					  newDefault != NULL);
 
 	if (newDefault)
@@ -7590,7 +7590,7 @@ ATExecColumnDefault(Relation rel, const char *colName,
 		RawColumnDefault *rawEnt;
 
 		rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault));
-		rawEnt->attnum = attnum;
+		rawEnt->attphysnum = attphysnum;
 		rawEnt->raw_default = newDefault;
 		rawEnt->missingMode = false;
 		rawEnt->generated = '\0';
@@ -7604,7 +7604,7 @@ ATExecColumnDefault(Relation rel, const char *colName,
 	}
 
 	ObjectAddressSubSet(address, RelationRelationId,
-						RelationGetRelid(rel), attnum);
+						RelationGetRelid(rel), attphysnum);
 	return address;
 }
 
@@ -7614,7 +7614,7 @@ ATExecColumnDefault(Relation rel, const char *colName,
  * Return the address of the affected column.
  */
 static ObjectAddress
-ATExecCookedColumnDefault(Relation rel, AttrNumber attnum,
+ATExecCookedColumnDefault(Relation rel, AttrNumber attphysnum,
 						  Node *newDefault)
 {
 	ObjectAddress address;
@@ -7627,13 +7627,13 @@ ATExecCookedColumnDefault(Relation rel, AttrNumber attnum,
 	 * default.  (In ordinary cases, there could not be a default in place
 	 * anyway, but it's possible when combining LIKE with inheritance.)
 	 */
-	RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, false,
+	RemoveAttrDefault(RelationGetRelid(rel), attphysnum, DROP_RESTRICT, false,
 					  true);
 
-	(void) StoreAttrDefault(rel, attnum, newDefault, true, false);
+	(void) StoreAttrDefault(rel, attphysnum, newDefault, true, false);
 
 	ObjectAddressSubSet(address, RelationRelationId,
-						RelationGetRelid(rel), attnum);
+						RelationGetRelid(rel), attphysnum);
 	return address;
 }
 
@@ -7649,7 +7649,7 @@ ATExecAddIdentity(Relation rel, const char *colName,
 	Relation	attrelation;
 	HeapTuple	tuple;
 	Form_pg_attribute attTup;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	ObjectAddress address;
 	ColumnDef  *cdef = castNode(ColumnDef, def);
 
@@ -7662,10 +7662,10 @@ ATExecAddIdentity(Relation rel, const char *colName,
 				 errmsg("column \"%s\" of relation \"%s\" does not exist",
 						colName, RelationGetRelationName(rel))));
 	attTup = (Form_pg_attribute) GETSTRUCT(tuple);
-	attnum = attTup->attnum;
+	attphysnum = attTup->attphysnum;
 
 	/* Can't alter a system attribute */
-	if (attnum <= 0)
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot alter system column \"%s\"",
@@ -7699,9 +7699,9 @@ ATExecAddIdentity(Relation rel, const char *colName,
 
 	InvokeObjectPostAlterHook(RelationRelationId,
 							  RelationGetRelid(rel),
-							  attTup->attnum);
+							  attTup->attphysnum);
 	ObjectAddressSubSet(address, RelationRelationId,
-						RelationGetRelid(rel), attnum);
+						RelationGetRelid(rel), attphysnum);
 	heap_freetuple(tuple);
 
 	table_close(attrelation, RowExclusiveLock);
@@ -7721,7 +7721,7 @@ ATExecSetIdentity(Relation rel, const char *colName, Node *def, LOCKMODE lockmod
 	DefElem    *generatedEl = NULL;
 	HeapTuple	tuple;
 	Form_pg_attribute attTup;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	Relation	attrelation;
 	ObjectAddress address;
 
@@ -7757,9 +7757,9 @@ ATExecSetIdentity(Relation rel, const char *colName, Node *def, LOCKMODE lockmod
 						colName, RelationGetRelationName(rel))));
 
 	attTup = (Form_pg_attribute) GETSTRUCT(tuple);
-	attnum = attTup->attnum;
+	attphysnum = attTup->attphysnum;
 
-	if (attnum <= 0)
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot alter system column \"%s\"",
@@ -7778,9 +7778,9 @@ ATExecSetIdentity(Relation rel, const char *colName, Node *def, LOCKMODE lockmod
 
 		InvokeObjectPostAlterHook(RelationRelationId,
 								  RelationGetRelid(rel),
-								  attTup->attnum);
+								  attTup->attphysnum);
 		ObjectAddressSubSet(address, RelationRelationId,
-							RelationGetRelid(rel), attnum);
+							RelationGetRelid(rel), attphysnum);
 	}
 	else
 		address = InvalidObjectAddress;
@@ -7801,7 +7801,7 @@ ATExecDropIdentity(Relation rel, const char *colName, bool missing_ok, LOCKMODE
 {
 	HeapTuple	tuple;
 	Form_pg_attribute attTup;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	Relation	attrelation;
 	ObjectAddress address;
 	Oid			seqid;
@@ -7816,9 +7816,9 @@ ATExecDropIdentity(Relation rel, const char *colName, bool missing_ok, LOCKMODE
 						colName, RelationGetRelationName(rel))));
 
 	attTup = (Form_pg_attribute) GETSTRUCT(tuple);
-	attnum = attTup->attnum;
+	attphysnum = attTup->attphysnum;
 
-	if (attnum <= 0)
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot alter system column \"%s\"",
@@ -7847,15 +7847,15 @@ ATExecDropIdentity(Relation rel, const char *colName, bool missing_ok, LOCKMODE
 
 	InvokeObjectPostAlterHook(RelationRelationId,
 							  RelationGetRelid(rel),
-							  attTup->attnum);
+							  attTup->attphysnum);
 	ObjectAddressSubSet(address, RelationRelationId,
-						RelationGetRelid(rel), attnum);
+						RelationGetRelid(rel), attphysnum);
 	heap_freetuple(tuple);
 
 	table_close(attrelation, RowExclusiveLock);
 
 	/* drop the internal sequence */
-	seqid = getIdentitySequence(RelationGetRelid(rel), attnum, false);
+	seqid = getIdentitySequence(RelationGetRelid(rel), attphysnum, false);
 	deleteDependencyRecordsForClass(RelationRelationId, seqid,
 									RelationRelationId, DEPENDENCY_INTERNAL);
 	CommandCounterIncrement();
@@ -7921,7 +7921,7 @@ ATExecDropExpression(Relation rel, const char *colName, bool missing_ok, LOCKMOD
 {
 	HeapTuple	tuple;
 	Form_pg_attribute attTup;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	Relation	attrelation;
 	Oid			attrdefoid;
 	ObjectAddress address;
@@ -7935,9 +7935,9 @@ ATExecDropExpression(Relation rel, const char *colName, bool missing_ok, LOCKMOD
 						colName, RelationGetRelationName(rel))));
 
 	attTup = (Form_pg_attribute) GETSTRUCT(tuple);
-	attnum = attTup->attnum;
+	attphysnum = attTup->attphysnum;
 
-	if (attnum <= 0)
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot alter system column \"%s\"",
@@ -7970,7 +7970,7 @@ ATExecDropExpression(Relation rel, const char *colName, bool missing_ok, LOCKMOD
 
 	InvokeObjectPostAlterHook(RelationRelationId,
 							  RelationGetRelid(rel),
-							  attnum);
+							  attphysnum);
 	heap_freetuple(tuple);
 
 	table_close(attrelation, RowExclusiveLock);
@@ -7980,10 +7980,10 @@ ATExecDropExpression(Relation rel, const char *colName, bool missing_ok, LOCKMOD
 	 * its INTERNAL dependency on the column, which would otherwise cause
 	 * dependency.c to refuse to perform the deletion.
 	 */
-	attrdefoid = GetAttrDefaultOid(RelationGetRelid(rel), attnum);
+	attrdefoid = GetAttrDefaultOid(RelationGetRelid(rel), attphysnum);
 	if (!OidIsValid(attrdefoid))
-		elog(ERROR, "could not find attrdef tuple for relation %u attnum %d",
-			 RelationGetRelid(rel), attnum);
+		elog(ERROR, "could not find attrdef tuple for relation %u attphysnum %d",
+			 RelationGetRelid(rel), attphysnum);
 	(void) deleteDependencyRecordsFor(AttrDefaultRelationId, attrdefoid, false);
 
 	/* Make above changes visible */
@@ -7994,11 +7994,11 @@ ATExecDropExpression(Relation rel, const char *colName, bool missing_ok, LOCKMOD
 	 * safety, but at present we do not expect anything to depend on the
 	 * default.
 	 */
-	RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT,
+	RemoveAttrDefault(RelationGetRelid(rel), attphysnum, DROP_RESTRICT,
 					  false, false);
 
 	ObjectAddressSubSet(address, RelationRelationId,
-						RelationGetRelid(rel), attnum);
+						RelationGetRelid(rel), attphysnum);
 	return address;
 }
 
@@ -8014,7 +8014,7 @@ ATExecSetStatistics(Relation rel, const char *colName, int16 colNum, Node *newVa
 	Relation	attrelation;
 	HeapTuple	tuple;
 	Form_pg_attribute attrtuple;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	ObjectAddress address;
 
 	/*
@@ -8075,8 +8075,8 @@ ATExecSetStatistics(Relation rel, const char *colName, int16 colNum, Node *newVa
 
 	attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
 
-	attnum = attrtuple->attnum;
-	if (attnum <= 0)
+	attphysnum = attrtuple->attphysnum;
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot alter system column \"%s\"",
@@ -8085,12 +8085,12 @@ ATExecSetStatistics(Relation rel, const char *colName, int16 colNum, Node *newVa
 	if (rel->rd_rel->relkind == RELKIND_INDEX ||
 		rel->rd_rel->relkind == RELKIND_PARTITIONED_INDEX)
 	{
-		if (attnum > rel->rd_index->indnkeyatts)
+		if (attphysnum > rel->rd_index->indnkeyatts)
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 					 errmsg("cannot alter statistics on included column \"%s\" of index \"%s\"",
 							NameStr(attrtuple->attname), RelationGetRelationName(rel))));
-		else if (rel->rd_index->indkey.values[attnum - 1] != 0)
+		else if (rel->rd_index->indkey.values[attphysnum - 1] != 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 					 errmsg("cannot alter statistics on non-expression column \"%s\" of index \"%s\"",
@@ -8104,9 +8104,9 @@ ATExecSetStatistics(Relation rel, const char *colName, int16 colNum, Node *newVa
 
 	InvokeObjectPostAlterHook(RelationRelationId,
 							  RelationGetRelid(rel),
-							  attrtuple->attnum);
+							  attrtuple->attphysnum);
 	ObjectAddressSubSet(address, RelationRelationId,
-						RelationGetRelid(rel), attnum);
+						RelationGetRelid(rel), attphysnum);
 	heap_freetuple(tuple);
 
 	table_close(attrelation, RowExclusiveLock);
@@ -8125,7 +8125,7 @@ ATExecSetOptions(Relation rel, const char *colName, Node *options,
 	HeapTuple	tuple,
 				newtuple;
 	Form_pg_attribute attrtuple;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	Datum		datum,
 				newOptions;
 	bool		isnull;
@@ -8145,8 +8145,8 @@ ATExecSetOptions(Relation rel, const char *colName, Node *options,
 						colName, RelationGetRelationName(rel))));
 	attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
 
-	attnum = attrtuple->attnum;
-	if (attnum <= 0)
+	attphysnum = attrtuple->attphysnum;
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot alter system column \"%s\"",
@@ -8177,9 +8177,9 @@ ATExecSetOptions(Relation rel, const char *colName, Node *options,
 
 	InvokeObjectPostAlterHook(RelationRelationId,
 							  RelationGetRelid(rel),
-							  attrtuple->attnum);
+							  attrtuple->attphysnum);
 	ObjectAddressSubSet(address, RelationRelationId,
-						RelationGetRelid(rel), attnum);
+						RelationGetRelid(rel), attphysnum);
 
 	heap_freetuple(newtuple);
 
@@ -8198,7 +8198,7 @@ ATExecSetOptions(Relation rel, const char *colName, Node *options,
  */
 static void
 SetIndexStorageProperties(Relation rel, Relation attrelation,
-						  AttrNumber attnum,
+						  AttrNumber attphysnum,
 						  bool setstorage, char newstorage,
 						  bool setcompression, char newcompression,
 						  LOCKMODE lockmode)
@@ -8216,7 +8216,7 @@ SetIndexStorageProperties(Relation rel, Relation attrelation,
 
 		for (int i = 0; i < indrel->rd_index->indnatts; i++)
 		{
-			if (indrel->rd_index->indkey.values[i] == attnum)
+			if (indrel->rd_index->indkey.values[i] == attphysnum)
 			{
 				indattnum = i + 1;
 				break;
@@ -8245,7 +8245,7 @@ SetIndexStorageProperties(Relation rel, Relation attrelation,
 
 			InvokeObjectPostAlterHook(RelationRelationId,
 									  RelationGetRelid(rel),
-									  attrtuple->attnum);
+									  attrtuple->attphysnum);
 
 			heap_freetuple(tuple);
 		}
@@ -8267,7 +8267,7 @@ ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE loc
 	Relation	attrelation;
 	HeapTuple	tuple;
 	Form_pg_attribute attrtuple;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	ObjectAddress address;
 
 	Assert(IsA(newValue, String));
@@ -8301,8 +8301,8 @@ ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE loc
 						colName, RelationGetRelationName(rel))));
 	attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
 
-	attnum = attrtuple->attnum;
-	if (attnum <= 0)
+	attphysnum = attrtuple->attphysnum;
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot alter system column \"%s\"",
@@ -8324,7 +8324,7 @@ ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE loc
 
 	InvokeObjectPostAlterHook(RelationRelationId,
 							  RelationGetRelid(rel),
-							  attrtuple->attnum);
+							  attrtuple->attphysnum);
 
 	heap_freetuple(tuple);
 
@@ -8332,7 +8332,7 @@ ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE loc
 	 * Apply the change to indexes as well (only for simple index columns,
 	 * matching behavior of index.c ConstructTupleDescriptor()).
 	 */
-	SetIndexStorageProperties(rel, attrelation, attnum,
+	SetIndexStorageProperties(rel, attrelation, attphysnum,
 							  true, newstorage,
 							  false, 0,
 							  lockmode);
@@ -8340,7 +8340,7 @@ ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE loc
 	table_close(attrelation, RowExclusiveLock);
 
 	ObjectAddressSubSet(address, RelationRelationId,
-						RelationGetRelid(rel), attnum);
+						RelationGetRelid(rel), attphysnum);
 	return address;
 }
 
@@ -8391,7 +8391,7 @@ ATExecDropColumn(List **wqueue, Relation rel, const char *colName,
 {
 	HeapTuple	tuple;
 	Form_pg_attribute targetatt;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	List	   *children;
 	ObjectAddress object;
 	bool		is_expr;
@@ -8428,10 +8428,10 @@ ATExecDropColumn(List **wqueue, Relation rel, const char *colName,
 	}
 	targetatt = (Form_pg_attribute) GETSTRUCT(tuple);
 
-	attnum = targetatt->attnum;
+	attphysnum = targetatt->attphysnum;
 
 	/* Can't drop a system attribute */
-	if (attnum <= 0)
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot drop system column \"%s\"",
@@ -8453,7 +8453,7 @@ ATExecDropColumn(List **wqueue, Relation rel, const char *colName,
 	 * of the whole table, which is surely not what the user expected.)
 	 */
 	if (has_partition_attrs(rel,
-							bms_make_singleton(attnum - FirstLowInvalidHeapAttributeNumber),
+							bms_make_singleton(attphysnum - FirstLowInvalidHeapAttributeNumber),
 							&is_expr))
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
@@ -8557,7 +8557,7 @@ ATExecDropColumn(List **wqueue, Relation rel, const char *colName,
 	/* Add object to delete */
 	object.classId = RelationRelationId;
 	object.objectId = RelationGetRelid(rel);
-	object.objectSubId = attnum;
+	object.objectSubId = attphysnum;
 	add_exact_object_address(&object, addrs);
 
 	if (!recursing)
@@ -9490,11 +9490,11 @@ validateFkOnDeleteSetColumns(int numfks, const int16 *fkattnums,
  * parentConstr is the OID of a parent constraint; InvalidOid if this is a
  * top-level constraint.
  * numfks is the number of columns in the foreign key
- * pkattnum is the attnum array of referenced attributes.
- * fkattnum is the attnum array of referencing attributes.
+ * pkattnum is the attphysnum array of referenced attributes.
+ * fkattnum is the attphysnum array of referencing attributes.
  * numfkdelsetcols is the number of columns in the ON DELETE SET NULL/DELETE
  *      (...) clause
- * fkdelsetcols is the attnum array of the columns in the ON DELETE SET
+ * fkdelsetcols is the attphysnum array of the columns in the ON DELETE SET
  *      NULL/DELETE clause
  * pf/pp/ffeqoperators are OID array of operators between columns.
  * old_check_ok signals that this constraint replaces an existing one that
@@ -9708,12 +9708,12 @@ addFkRecurseReferenced(List **wqueue, Constraint *fkconstraint, Relation rel,
  * indexOid is the OID of the index (on pkrel) implementing this constraint.
  * parentConstr is the OID of the parent constraint (there is always one).
  * numfks is the number of columns in the foreign key
- * pkattnum is the attnum array of referenced attributes.
- * fkattnum is the attnum array of referencing attributes.
+ * pkattnum is the attphysnum array of referenced attributes.
+ * fkattnum is the attphysnum array of referencing attributes.
  * pf/pp/ffeqoperators are OID array of operators between columns.
  * numfkdelsetcols is the number of columns in the ON DELETE SET NULL/DELETE
  *      (...) clause
- * fkdelsetcols is the attnum array of the columns in the ON DELETE SET
+ * fkdelsetcols is the attphysnum array of the columns in the ON DELETE SET
  *      NULL/DELETE clause
  * old_check_ok signals that this constraint replaces an existing one that
  *		was already validated (thus this one doesn't need validation).
@@ -11144,16 +11144,16 @@ ATExecValidateConstraint(List **wqueue, Relation rel, char *constrName,
 /*
  * transformColumnNameList - transform list of column names
  *
- * Lookup each name and return its attnum and, optionally, type OID
+ * Lookup each name and return its attphysnum and, optionally, type OID
  */
 static int
 transformColumnNameList(Oid relId, List *colList,
 						int16 *attnums, Oid *atttypids)
 {
 	ListCell   *l;
-	int			attnum;
+	int			attphysnum;
 
-	attnum = 0;
+	attphysnum = 0;
 	foreach(l, colList)
 	{
 		char	   *attname = strVal(lfirst(l));
@@ -11165,19 +11165,19 @@ transformColumnNameList(Oid relId, List *colList,
 					(errcode(ERRCODE_UNDEFINED_COLUMN),
 					 errmsg("column \"%s\" referenced in foreign key constraint does not exist",
 							attname)));
-		if (attnum >= INDEX_MAX_KEYS)
+		if (attphysnum >= INDEX_MAX_KEYS)
 			ereport(ERROR,
 					(errcode(ERRCODE_TOO_MANY_COLUMNS),
 					 errmsg("cannot have more than %d keys in a foreign key",
 							INDEX_MAX_KEYS)));
-		attnums[attnum] = ((Form_pg_attribute) GETSTRUCT(atttuple))->attnum;
+		attnums[attphysnum] = ((Form_pg_attribute) GETSTRUCT(atttuple))->attphysnum;
 		if (atttypids != NULL)
-			atttypids[attnum] = ((Form_pg_attribute) GETSTRUCT(atttuple))->atttypid;
+			atttypids[attphysnum] = ((Form_pg_attribute) GETSTRUCT(atttuple))->atttypid;
 		ReleaseSysCache(atttuple);
-		attnum++;
+		attphysnum++;
 	}
 
-	return attnum;
+	return attphysnum;
 }
 
 /*
@@ -11360,7 +11360,7 @@ transformFkeyCheckAttrs(Relation pkrel,
 			indclass = (oidvector *) DatumGetPointer(indclassDatum);
 
 			/*
-			 * The given attnum list may match the index columns in any order.
+			 * The given attphysnum list may match the index columns in any order.
 			 * Check for a match, and extract the appropriate opclasses while
 			 * we're at it.
 			 *
@@ -12070,7 +12070,7 @@ ATPrepAlterColumnType(List **wqueue,
 	Node	   *transform = def->cooked_default;
 	HeapTuple	tuple;
 	Form_pg_attribute attTup;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	Oid			targettype;
 	int32		targettypmod;
 	Oid			targetcollid;
@@ -12092,10 +12092,10 @@ ATPrepAlterColumnType(List **wqueue,
 				 errmsg("column \"%s\" of relation \"%s\" does not exist",
 						colName, RelationGetRelationName(rel))));
 	attTup = (Form_pg_attribute) GETSTRUCT(tuple);
-	attnum = attTup->attnum;
+	attphysnum = attTup->attphysnum;
 
 	/* Can't alter a system attribute */
-	if (attnum <= 0)
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot alter system column \"%s\"",
@@ -12114,7 +12114,7 @@ ATPrepAlterColumnType(List **wqueue,
 
 	/* Don't alter columns used in the partition key */
 	if (has_partition_attrs(rel,
-							bms_make_singleton(attnum - FirstLowInvalidHeapAttributeNumber),
+							bms_make_singleton(attphysnum - FirstLowInvalidHeapAttributeNumber),
 							&is_expr))
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
@@ -12150,7 +12150,7 @@ ATPrepAlterColumnType(List **wqueue,
 		 */
 		if (!transform)
 		{
-			transform = (Node *) makeVar(1, attnum,
+			transform = (Node *) makeVar(1, attphysnum,
 										 attTup->atttypid, attTup->atttypmod,
 										 attTup->attcollation,
 										 0);
@@ -12195,12 +12195,12 @@ ATPrepAlterColumnType(List **wqueue,
 		 * contents.
 		 */
 		newval = (NewColumnValue *) palloc0(sizeof(NewColumnValue));
-		newval->attnum = attnum;
+		newval->attphysnum = attphysnum;
 		newval->expr = (Expr *) transform;
 		newval->is_generated = false;
 
 		tab->newvals = lappend(tab->newvals, newval);
-		if (ATColumnChangeRequiresRewrite(transform, attnum))
+		if (ATColumnChangeRequiresRewrite(transform, attphysnum))
 			tab->rewrite |= AT_REWRITE_COLUMN_REWRITE;
 	}
 	else if (transform)
@@ -12394,7 +12394,7 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 	HeapTuple	heapTup;
 	Form_pg_attribute attTup,
 				attOldTup;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	HeapTuple	typeTuple;
 	Form_pg_type tform;
 	Oid			targettype;
@@ -12433,8 +12433,8 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 				 errmsg("column \"%s\" of relation \"%s\" does not exist",
 						colName, RelationGetRelationName(rel))));
 	attTup = (Form_pg_attribute) GETSTRUCT(heapTup);
-	attnum = attTup->attnum;
-	attOldTup = TupleDescAttr(tab->oldDesc, attnum - 1);
+	attphysnum = attTup->attphysnum;
+	attOldTup = TupleDescAttr(tab->oldDesc, attphysnum - 1);
 
 	/* Check for multiple ALTER TYPE on same column --- can't cope */
 	if (attTup->atttypid != attOldTup->atttypid ||
@@ -12465,7 +12465,7 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 	 */
 	if (attTup->atthasdef)
 	{
-		defaultexpr = build_column_default(rel, attnum);
+		defaultexpr = build_column_default(rel, attphysnum);
 		Assert(defaultexpr);
 		defaultexpr = strip_implicit_coercions(defaultexpr);
 		defaultexpr = coerce_to_target_type(NULL,	/* no UNKNOWN params */
@@ -12513,7 +12513,7 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 	ScanKeyInit(&key[2],
 				Anum_pg_depend_refobjsubid,
 				BTEqualStrategyNumber, F_INT4EQ,
-				Int32GetDatum((int32) attnum));
+				Int32GetDatum((int32) attphysnum));
 
 	scan = systable_beginscan(depRel, DependReferenceIndexId, true,
 							  NULL, 3, key);
@@ -12613,7 +12613,7 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 					ObjectAddress col = GetAttrDefaultColumnAddress(foundObject.objectId);
 
 					if (col.objectId == RelationGetRelid(rel) &&
-						col.objectSubId == attnum)
+						col.objectSubId == attphysnum)
 					{
 						/*
 						 * Ignore the column's own default expression, which
@@ -12719,7 +12719,7 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 	ScanKeyInit(&key[2],
 				Anum_pg_depend_objsubid,
 				BTEqualStrategyNumber, F_INT4EQ,
-				Int32GetDatum((int32) attnum));
+				Int32GetDatum((int32) attphysnum));
 
 	scan = systable_beginscan(depRel, DependDependerIndexId, true,
 							  NULL, 3, key);
@@ -12835,16 +12835,16 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 	table_close(attrelation, RowExclusiveLock);
 
 	/* Install dependencies on new datatype and collation */
-	add_column_datatype_dependency(RelationGetRelid(rel), attnum, targettype);
-	add_column_collation_dependency(RelationGetRelid(rel), attnum, targetcollid);
+	add_column_datatype_dependency(RelationGetRelid(rel), attphysnum, targettype);
+	add_column_collation_dependency(RelationGetRelid(rel), attphysnum, targetcollid);
 
 	/*
 	 * Drop any pg_statistic entry for the column, since it's now wrong type
 	 */
-	RemoveStatistics(RelationGetRelid(rel), attnum);
+	RemoveStatistics(RelationGetRelid(rel), attphysnum);
 
 	InvokeObjectPostAlterHook(RelationRelationId,
-							  RelationGetRelid(rel), attnum);
+							  RelationGetRelid(rel), attphysnum);
 
 	/*
 	 * Update the default, if present, by brute force --- remove and re-add
@@ -12862,11 +12862,11 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 		 */
 		if (attTup->attgenerated)
 		{
-			Oid			attrdefoid = GetAttrDefaultOid(RelationGetRelid(rel), attnum);
+			Oid			attrdefoid = GetAttrDefaultOid(RelationGetRelid(rel), attphysnum);
 
 			if (!OidIsValid(attrdefoid))
-				elog(ERROR, "could not find attrdef tuple for relation %u attnum %d",
-					 RelationGetRelid(rel), attnum);
+				elog(ERROR, "could not find attrdef tuple for relation %u attphysnum %d",
+					 RelationGetRelid(rel), attphysnum);
 			(void) deleteDependencyRecordsFor(AttrDefaultRelationId, attrdefoid, false);
 		}
 
@@ -12880,14 +12880,14 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 		 * We use RESTRICT here for safety, but at present we do not expect
 		 * anything to depend on the default.
 		 */
-		RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, true,
+		RemoveAttrDefault(RelationGetRelid(rel), attphysnum, DROP_RESTRICT, true,
 						  true);
 
-		StoreAttrDefault(rel, attnum, defaultexpr, true, false);
+		StoreAttrDefault(rel, attphysnum, defaultexpr, true, false);
 	}
 
 	ObjectAddressSubSet(address, RelationRelationId,
-						RelationGetRelid(rel), attnum);
+						RelationGetRelid(rel), attphysnum);
 
 	/* Cleanup */
 	heap_freetuple(heapTup);
@@ -13568,7 +13568,7 @@ ATExecAlterColumnGenericOptions(Relation rel,
 	Datum		datum;
 	Form_pg_foreign_table fttableform;
 	Form_pg_attribute atttableform;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	ObjectAddress address;
 
 	if (options == NIL)
@@ -13599,8 +13599,8 @@ ATExecAlterColumnGenericOptions(Relation rel,
 
 	/* Prevent them from altering a system attribute */
 	atttableform = (Form_pg_attribute) GETSTRUCT(tuple);
-	attnum = atttableform->attnum;
-	if (attnum <= 0)
+	attphysnum = atttableform->attphysnum;
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot alter system column \"%s\"", colName)));
@@ -13641,9 +13641,9 @@ ATExecAlterColumnGenericOptions(Relation rel,
 
 	InvokeObjectPostAlterHook(RelationRelationId,
 							  RelationGetRelid(rel),
-							  atttableform->attnum);
+							  atttableform->attphysnum);
 	ObjectAddressSubSet(address, RelationRelationId,
-						RelationGetRelid(rel), attnum);
+						RelationGetRelid(rel), attphysnum);
 
 	ReleaseSysCache(tuple);
 
@@ -13918,7 +13918,7 @@ change_owner_fix_column_acls(Oid relationOid, Oid oldOwnerId, Oid newOwnerId)
 				Anum_pg_attribute_attrelid,
 				BTEqualStrategyNumber, F_OIDEQ,
 				ObjectIdGetDatum(relationOid));
-	scan = systable_beginscan(attRelation, AttributeRelidNumIndexId,
+	scan = systable_beginscan(attRelation, AttributeRelidPhysNumIndexId,
 							  true, NULL, 1, key);
 	while (HeapTupleIsValid(attributeTuple = systable_getnext(scan)))
 	{
@@ -15062,7 +15062,7 @@ MergeAttributesIntoExisting(Relation child_rel, Relation parent_rel)
 
 				for (int i = 0; i < child_constr->num_defval; i++)
 				{
-					if (child_constr->defval[i].adnum == childatt->attnum)
+					if (child_constr->defval[i].adnum == childatt->attphysnum)
 					{
 						child_expr =
 							TextDatumGetCString(DirectFunctionCall2(pg_get_expr,
@@ -15075,7 +15075,7 @@ MergeAttributesIntoExisting(Relation child_rel, Relation parent_rel)
 
 				for (int i = 0; i < parent_constr->num_defval; i++)
 				{
-					if (parent_constr->defval[i].adnum == attribute->attnum)
+					if (parent_constr->defval[i].adnum == attribute->attphysnum)
 					{
 						parent_expr =
 							TextDatumGetCString(DirectFunctionCall2(pg_get_expr,
@@ -15441,7 +15441,7 @@ RemoveInheritance(Relation child_rel, Relation parent_rel, bool expect_detached)
 				Anum_pg_attribute_attrelid,
 				BTEqualStrategyNumber, F_OIDEQ,
 				ObjectIdGetDatum(RelationGetRelid(child_rel)));
-	scan = systable_beginscan(catalogRelation, AttributeRelidNumIndexId,
+	scan = systable_beginscan(catalogRelation, AttributeRelidPhysNumIndexId,
 							  true, NULL, 1, key);
 	while (HeapTupleIsValid(attributeTuple = systable_getnext(scan)))
 	{
@@ -16165,7 +16165,7 @@ ATExecSetCompression(AlteredTableInfo *tab,
 	Relation	attrel;
 	HeapTuple	tuple;
 	Form_pg_attribute atttableform;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	char	   *compression;
 	char		cmethod;
 	ObjectAddress address;
@@ -16185,8 +16185,8 @@ ATExecSetCompression(AlteredTableInfo *tab,
 
 	/* prevent them from altering a system attribute */
 	atttableform = (Form_pg_attribute) GETSTRUCT(tuple);
-	attnum = atttableform->attnum;
-	if (attnum <= 0)
+	attphysnum = atttableform->attphysnum;
+	if (attphysnum <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot alter system column \"%s\"", column)));
@@ -16203,13 +16203,13 @@ ATExecSetCompression(AlteredTableInfo *tab,
 
 	InvokeObjectPostAlterHook(RelationRelationId,
 							  RelationGetRelid(rel),
-							  attnum);
+							  attphysnum);
 
 	/*
 	 * Apply the change to indexes as well (only for simple index columns,
 	 * matching behavior of index.c ConstructTupleDescriptor()).
 	 */
-	SetIndexStorageProperties(rel, attrel, attnum,
+	SetIndexStorageProperties(rel, attrel, attphysnum,
 							  false, 0,
 							  true, cmethod,
 							  lockmode);
@@ -16222,7 +16222,7 @@ ATExecSetCompression(AlteredTableInfo *tab,
 	CommandCounterIncrement();
 
 	ObjectAddressSubSet(address, RelationRelationId,
-						RelationGetRelid(rel), attnum);
+						RelationGetRelid(rel), attphysnum);
 	return address;
 }
 
@@ -17247,7 +17247,7 @@ ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNu
 						 parser_errposition(pstate, pelem->location)));
 			attform = (Form_pg_attribute) GETSTRUCT(atttuple);
 
-			if (attform->attnum <= 0)
+			if (attform->attphysnum <= 0)
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
 						 errmsg("cannot use system column \"%s\" in partition key",
@@ -17266,7 +17266,7 @@ ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNu
 								   pelem->name),
 						 parser_errposition(pstate, pelem->location)));
 
-			partattrs[attn] = attform->attnum;
+			partattrs[attn] = attform->attphysnum;
 			atttype = attform->atttypid;
 			attcollation = attform->attcollation;
 			ReleaseSysCache(atttuple);
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index 13cb516752..b67128e9fe 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -947,12 +947,12 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
 		foreach(cell, stmt->columns)
 		{
 			char	   *name = strVal(lfirst(cell));
-			int16		attnum;
+			int16		attphysnum;
 			int			j;
 
 			/* Lookup column name.  System columns are not allowed */
-			attnum = attnameAttNum(rel, name, false);
-			if (attnum == InvalidAttrNumber)
+			attphysnum = attnameAttNum(rel, name, false);
+			if (attphysnum == InvalidAttrNumber)
 				ereport(ERROR,
 						(errcode(ERRCODE_UNDEFINED_COLUMN),
 						 errmsg("column \"%s\" of relation \"%s\" does not exist",
@@ -961,14 +961,14 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
 			/* Check for duplicates */
 			for (j = i - 1; j >= 0; j--)
 			{
-				if (columns[j] == attnum)
+				if (columns[j] == attphysnum)
 					ereport(ERROR,
 							(errcode(ERRCODE_DUPLICATE_COLUMN),
 							 errmsg("column \"%s\" specified more than once",
 									name)));
 			}
 
-			columns[i++] = attnum;
+			columns[i++] = attphysnum;
 		}
 	}
 	tgattr = buildint2vector(columns, ncolumns);
diff --git a/src/backend/commands/tsearchcmds.c b/src/backend/commands/tsearchcmds.c
index 4cc4e3c00f..0797ee67f7 100644
--- a/src/backend/commands/tsearchcmds.c
+++ b/src/backend/commands/tsearchcmds.c
@@ -62,10 +62,10 @@ static DefElem *buildDefItem(const char *name, const char *val,
 /*
  * lookup a parser support function and return its OID (as a Datum)
  *
- * attnum is the pg_ts_parser column the function will go into
+ * attphysnum is the pg_ts_parser column the function will go into
  */
 static Datum
-get_ts_parser_func(DefElem *defel, int attnum)
+get_ts_parser_func(DefElem *defel, int attphysnum)
 {
 	List	   *funcName = defGetQualifiedName(defel);
 	Oid			typeId[3];
@@ -75,7 +75,7 @@ get_ts_parser_func(DefElem *defel, int attnum)
 
 	retTypeId = INTERNALOID;	/* correct for most */
 	typeId[0] = INTERNALOID;
-	switch (attnum)
+	switch (attphysnum)
 	{
 		case Anum_pg_ts_parser_prsstart:
 			nargs = 2;
@@ -107,7 +107,7 @@ get_ts_parser_func(DefElem *defel, int attnum)
 		default:
 			/* should not be here */
 			elog(ERROR, "unrecognized attribute for text search parser: %d",
-				 attnum);
+				 attphysnum);
 			nargs = 0;			/* keep compiler quiet */
 	}
 
@@ -597,10 +597,10 @@ AlterTSDictionary(AlterTSDictionaryStmt *stmt)
 /*
  * lookup a template support function and return its OID (as a Datum)
  *
- * attnum is the pg_ts_template column the function will go into
+ * attphysnum is the pg_ts_template column the function will go into
  */
 static Datum
-get_ts_template_func(DefElem *defel, int attnum)
+get_ts_template_func(DefElem *defel, int attphysnum)
 {
 	List	   *funcName = defGetQualifiedName(defel);
 	Oid			typeId[4];
@@ -613,7 +613,7 @@ get_ts_template_func(DefElem *defel, int attnum)
 	typeId[1] = INTERNALOID;
 	typeId[2] = INTERNALOID;
 	typeId[3] = INTERNALOID;
-	switch (attnum)
+	switch (attphysnum)
 	{
 		case Anum_pg_ts_template_tmplinit:
 			nargs = 1;
@@ -624,7 +624,7 @@ get_ts_template_func(DefElem *defel, int attnum)
 		default:
 			/* should not be here */
 			elog(ERROR, "unrecognized attribute for text search template: %d",
-				 attnum);
+				 attphysnum);
 			nargs = 0;			/* keep compiler quiet */
 	}
 
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 9b92b04242..e59afbe7cd 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -2758,10 +2758,10 @@ AlterDomainNotNull(List *names, bool notNull)
 				/* Test attributes that are of the domain */
 				for (i = 0; i < rtc->natts; i++)
 				{
-					int			attnum = rtc->atts[i];
-					Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
+					int			attphysnum = rtc->atts[i];
+					Form_pg_attribute attr = TupleDescAttr(tupdesc, attphysnum - 1);
 
-					if (slot_attisnull(slot, attnum))
+					if (slot_attisnull(slot, attphysnum))
 					{
 						/*
 						 * In principle the auxiliary information for this
@@ -2776,7 +2776,7 @@ AlterDomainNotNull(List *names, bool notNull)
 								 errmsg("column \"%s\" of table \"%s\" contains null values",
 										NameStr(attr->attname),
 										RelationGetRelationName(testrel)),
-								 errtablecol(testrel, attnum)));
+								 errtablecol(testrel, attphysnum)));
 					}
 				}
 			}
@@ -3174,13 +3174,13 @@ validateDomainConstraint(Oid domainoid, char *ccbin)
 			/* Test attributes that are of the domain */
 			for (i = 0; i < rtc->natts; i++)
 			{
-				int			attnum = rtc->atts[i];
+				int			attphysnum = rtc->atts[i];
 				Datum		d;
 				bool		isNull;
 				Datum		conResult;
-				Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
+				Form_pg_attribute attr = TupleDescAttr(tupdesc, attphysnum - 1);
 
-				d = slot_getattr(slot, attnum, &isNull);
+				d = slot_getattr(slot, attphysnum, &isNull);
 
 				econtext->domainValue_datum = d;
 				econtext->domainValue_isNull = isNull;
@@ -3204,7 +3204,7 @@ validateDomainConstraint(Oid domainoid, char *ccbin)
 							 errmsg("column \"%s\" of table \"%s\" contains values that violate the new constraint",
 									NameStr(attr->attname),
 									RelationGetRelationName(testrel)),
-							 errtablecol(testrel, attnum)));
+							 errtablecol(testrel, attphysnum)));
 				}
 			}
 
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index 2831e7978b..63e0617430 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -379,7 +379,7 @@ ExecBuildProjectionInfo(List *targetList,
 	{
 		TargetEntry *tle = lfirst_node(TargetEntry, lc);
 		Var		   *variable = NULL;
-		AttrNumber	attnum = 0;
+		AttrNumber	attphysnum = 0;
 		bool		isSafeVar = false;
 
 		/*
@@ -396,13 +396,13 @@ ExecBuildProjectionInfo(List *targetList,
 		{
 			/* Non-system Var, but how safe is it? */
 			variable = (Var *) tle->expr;
-			attnum = variable->varattno;
+			attphysnum = variable->varattno;
 
 			if (inputDesc == NULL)
 				isSafeVar = true;	/* can't check, just assume OK */
-			else if (attnum <= inputDesc->natts)
+			else if (attphysnum <= inputDesc->natts)
 			{
-				Form_pg_attribute attr = TupleDescAttr(inputDesc, attnum - 1);
+				Form_pg_attribute attr = TupleDescAttr(inputDesc, attphysnum - 1);
 
 				/*
 				 * If user attribute is dropped or has a type mismatch, don't
@@ -439,7 +439,7 @@ ExecBuildProjectionInfo(List *targetList,
 					break;
 			}
 
-			scratch.d.assign_var.attnum = attnum - 1;
+			scratch.d.assign_var.attphysnum = attphysnum - 1;
 			scratch.d.assign_var.resultnum = tle->resno - 1;
 			ExprEvalPushStep(state, &scratch);
 		}
@@ -584,15 +584,15 @@ ExecBuildUpdateProjection(List *targetList,
 	 * sufficiently deconstructed.  The scan tuple must be deconstructed at
 	 * least as far as the last old column we need.
 	 */
-	for (int attnum = relDesc->natts; attnum > 0; attnum--)
+	for (int attphysnum = relDesc->natts; attphysnum > 0; attphysnum--)
 	{
-		Form_pg_attribute attr = TupleDescAttr(relDesc, attnum - 1);
+		Form_pg_attribute attr = TupleDescAttr(relDesc, attphysnum - 1);
 
 		if (attr->attisdropped)
 			continue;
-		if (bms_is_member(attnum, assignedCols))
+		if (bms_is_member(attphysnum, assignedCols))
 			continue;
-		deform.last_scan = attnum;
+		deform.last_scan = attphysnum;
 		break;
 	}
 
@@ -668,7 +668,7 @@ ExecBuildUpdateProjection(List *targetList,
 		{
 			/* Just assign from the outer tuple. */
 			scratch.opcode = EEOP_ASSIGN_OUTER_VAR;
-			scratch.d.assign_var.attnum = outerattnum;
+			scratch.d.assign_var.attphysnum = outerattnum;
 			scratch.d.assign_var.resultnum = targetattnum - 1;
 			ExprEvalPushStep(state, &scratch);
 		}
@@ -695,9 +695,9 @@ ExecBuildUpdateProjection(List *targetList,
 	 * Now generate code to copy over any old columns that were not assigned
 	 * to, and to ensure that dropped columns are set to NULL.
 	 */
-	for (int attnum = 1; attnum <= relDesc->natts; attnum++)
+	for (int attphysnum = 1; attphysnum <= relDesc->natts; attphysnum++)
 	{
-		Form_pg_attribute attr = TupleDescAttr(relDesc, attnum - 1);
+		Form_pg_attribute attr = TupleDescAttr(relDesc, attphysnum - 1);
 
 		if (attr->attisdropped)
 		{
@@ -710,15 +710,15 @@ ExecBuildUpdateProjection(List *targetList,
 			ExprEvalPushStep(state, &scratch);
 			/* ... then assign it to the result slot */
 			scratch.opcode = EEOP_ASSIGN_TMP;
-			scratch.d.assign_tmp.resultnum = attnum - 1;
+			scratch.d.assign_tmp.resultnum = attphysnum - 1;
 			ExprEvalPushStep(state, &scratch);
 		}
-		else if (!bms_is_member(attnum, assignedCols))
+		else if (!bms_is_member(attphysnum, assignedCols))
 		{
 			/* Certainly the right type, so needn't check */
 			scratch.opcode = EEOP_ASSIGN_SCAN_VAR;
-			scratch.d.assign_var.attnum = attnum - 1;
-			scratch.d.assign_var.resultnum = attnum - 1;
+			scratch.d.assign_var.attphysnum = attphysnum - 1;
+			scratch.d.assign_var.resultnum = attphysnum - 1;
 			ExprEvalPushStep(state, &scratch);
 		}
 	}
@@ -925,7 +925,7 @@ ExecInitExprRec(Expr *node, ExprState *state,
 				else if (variable->varattno <= 0)
 				{
 					/* system column */
-					scratch.d.var.attnum = variable->varattno;
+					scratch.d.var.attphysnum = variable->varattno;
 					scratch.d.var.vartype = variable->vartype;
 					switch (variable->varno)
 					{
@@ -946,7 +946,7 @@ ExecInitExprRec(Expr *node, ExprState *state,
 				else
 				{
 					/* regular user column */
-					scratch.d.var.attnum = variable->varattno - 1;
+					scratch.d.var.attphysnum = variable->varattno - 1;
 					scratch.d.var.vartype = variable->vartype;
 					switch (variable->varno)
 					{
@@ -2890,22 +2890,22 @@ get_last_attnums_walker(Node *node, LastAttnumInfo *info)
 	if (IsA(node, Var))
 	{
 		Var		   *variable = (Var *) node;
-		AttrNumber	attnum = variable->varattno;
+		AttrNumber	attphysnum = variable->varattno;
 
 		switch (variable->varno)
 		{
 			case INNER_VAR:
-				info->last_inner = Max(info->last_inner, attnum);
+				info->last_inner = Max(info->last_inner, attphysnum);
 				break;
 
 			case OUTER_VAR:
-				info->last_outer = Max(info->last_outer, attnum);
+				info->last_outer = Max(info->last_outer, attphysnum);
 				break;
 
 				/* INDEX_VAR is handled by default case */
 
 			default:
-				info->last_scan = Max(info->last_scan, attnum);
+				info->last_scan = Max(info->last_scan, attphysnum);
 				break;
 		}
 		return false;
@@ -4040,7 +4040,7 @@ ExecBuildGroupingEqual(TupleDesc ldesc, TupleDesc rdesc,
 
 		/* left arg */
 		scratch.opcode = EEOP_INNER_VAR;
-		scratch.d.var.attnum = attno - 1;
+		scratch.d.var.attphysnum = attno - 1;
 		scratch.d.var.vartype = latt->atttypid;
 		scratch.resvalue = &fcinfo->args[0].value;
 		scratch.resnull = &fcinfo->args[0].isnull;
@@ -4048,7 +4048,7 @@ ExecBuildGroupingEqual(TupleDesc ldesc, TupleDesc rdesc,
 
 		/* right arg */
 		scratch.opcode = EEOP_OUTER_VAR;
-		scratch.d.var.attnum = attno - 1;
+		scratch.d.var.attphysnum = attno - 1;
 		scratch.d.var.vartype = ratt->atttypid;
 		scratch.resvalue = &fcinfo->args[1].value;
 		scratch.resnull = &fcinfo->args[1].isnull;
@@ -4174,7 +4174,7 @@ ExecBuildParamSetEqual(TupleDesc desc,
 
 		/* left arg */
 		scratch.opcode = EEOP_INNER_VAR;
-		scratch.d.var.attnum = attno;
+		scratch.d.var.attphysnum = attno;
 		scratch.d.var.vartype = att->atttypid;
 		scratch.resvalue = &fcinfo->args[0].value;
 		scratch.resnull = &fcinfo->args[0].isnull;
@@ -4182,7 +4182,7 @@ ExecBuildParamSetEqual(TupleDesc desc,
 
 		/* right arg */
 		scratch.opcode = EEOP_OUTER_VAR;
-		scratch.d.var.attnum = attno;
+		scratch.d.var.attphysnum = attno;
 		scratch.d.var.vartype = att->atttypid;
 		scratch.resvalue = &fcinfo->args[1].value;
 		scratch.resnull = &fcinfo->args[1].isnull;
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index eaec697bb3..fcc2f346bf 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -151,7 +151,7 @@ static Datum ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnul
 static void ExecInitInterpreter(void);
 
 /* support functions */
-static void CheckVarSlotCompatibility(TupleTableSlot *slot, int attnum, Oid vartype);
+static void CheckVarSlotCompatibility(TupleTableSlot *slot, int attphysnum, Oid vartype);
 static void CheckOpSlotCompatibility(ExprEvalStep *op, TupleTableSlot *slot);
 static TupleDesc get_cached_rowtype(Oid type_id, int32 typmod,
 									ExprEvalRowtypeCache *rowcache,
@@ -561,7 +561,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 
 		EEO_CASE(EEOP_INNER_VAR)
 		{
-			int			attnum = op->d.var.attnum;
+			int			attphysnum = op->d.var.attphysnum;
 
 			/*
 			 * Since we already extracted all referenced columns from the
@@ -569,35 +569,35 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 			 * directly out of the slot's decomposed-data arrays.  But let's
 			 * have an Assert to check that that did happen.
 			 */
-			Assert(attnum >= 0 && attnum < innerslot->tts_nvalid);
-			*op->resvalue = innerslot->tts_values[attnum];
-			*op->resnull = innerslot->tts_isnull[attnum];
+			Assert(attphysnum >= 0 && attphysnum < innerslot->tts_nvalid);
+			*op->resvalue = innerslot->tts_values[attphysnum];
+			*op->resnull = innerslot->tts_isnull[attphysnum];
 
 			EEO_NEXT();
 		}
 
 		EEO_CASE(EEOP_OUTER_VAR)
 		{
-			int			attnum = op->d.var.attnum;
+			int			attphysnum = op->d.var.attphysnum;
 
 			/* See EEOP_INNER_VAR comments */
 
-			Assert(attnum >= 0 && attnum < outerslot->tts_nvalid);
-			*op->resvalue = outerslot->tts_values[attnum];
-			*op->resnull = outerslot->tts_isnull[attnum];
+			Assert(attphysnum >= 0 && attphysnum < outerslot->tts_nvalid);
+			*op->resvalue = outerslot->tts_values[attphysnum];
+			*op->resnull = outerslot->tts_isnull[attphysnum];
 
 			EEO_NEXT();
 		}
 
 		EEO_CASE(EEOP_SCAN_VAR)
 		{
-			int			attnum = op->d.var.attnum;
+			int			attphysnum = op->d.var.attphysnum;
 
 			/* See EEOP_INNER_VAR comments */
 
-			Assert(attnum >= 0 && attnum < scanslot->tts_nvalid);
-			*op->resvalue = scanslot->tts_values[attnum];
-			*op->resnull = scanslot->tts_isnull[attnum];
+			Assert(attphysnum >= 0 && attphysnum < scanslot->tts_nvalid);
+			*op->resvalue = scanslot->tts_values[attphysnum];
+			*op->resnull = scanslot->tts_isnull[attphysnum];
 
 			EEO_NEXT();
 		}
@@ -631,16 +631,16 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 		EEO_CASE(EEOP_ASSIGN_INNER_VAR)
 		{
 			int			resultnum = op->d.assign_var.resultnum;
-			int			attnum = op->d.assign_var.attnum;
+			int			attphysnum = op->d.assign_var.attphysnum;
 
 			/*
 			 * We do not need CheckVarSlotCompatibility here; that was taken
 			 * care of at compilation time.  But see EEOP_INNER_VAR comments.
 			 */
-			Assert(attnum >= 0 && attnum < innerslot->tts_nvalid);
+			Assert(attphysnum >= 0 && attphysnum < innerslot->tts_nvalid);
 			Assert(resultnum >= 0 && resultnum < resultslot->tts_tupleDescriptor->natts);
-			resultslot->tts_values[resultnum] = innerslot->tts_values[attnum];
-			resultslot->tts_isnull[resultnum] = innerslot->tts_isnull[attnum];
+			resultslot->tts_values[resultnum] = innerslot->tts_values[attphysnum];
+			resultslot->tts_isnull[resultnum] = innerslot->tts_isnull[attphysnum];
 
 			EEO_NEXT();
 		}
@@ -648,16 +648,16 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 		EEO_CASE(EEOP_ASSIGN_OUTER_VAR)
 		{
 			int			resultnum = op->d.assign_var.resultnum;
-			int			attnum = op->d.assign_var.attnum;
+			int			attphysnum = op->d.assign_var.attphysnum;
 
 			/*
 			 * We do not need CheckVarSlotCompatibility here; that was taken
 			 * care of at compilation time.  But see EEOP_INNER_VAR comments.
 			 */
-			Assert(attnum >= 0 && attnum < outerslot->tts_nvalid);
+			Assert(attphysnum >= 0 && attphysnum < outerslot->tts_nvalid);
 			Assert(resultnum >= 0 && resultnum < resultslot->tts_tupleDescriptor->natts);
-			resultslot->tts_values[resultnum] = outerslot->tts_values[attnum];
-			resultslot->tts_isnull[resultnum] = outerslot->tts_isnull[attnum];
+			resultslot->tts_values[resultnum] = outerslot->tts_values[attphysnum];
+			resultslot->tts_isnull[resultnum] = outerslot->tts_isnull[attphysnum];
 
 			EEO_NEXT();
 		}
@@ -665,16 +665,16 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 		EEO_CASE(EEOP_ASSIGN_SCAN_VAR)
 		{
 			int			resultnum = op->d.assign_var.resultnum;
-			int			attnum = op->d.assign_var.attnum;
+			int			attphysnum = op->d.assign_var.attphysnum;
 
 			/*
 			 * We do not need CheckVarSlotCompatibility here; that was taken
 			 * care of at compilation time.  But see EEOP_INNER_VAR comments.
 			 */
-			Assert(attnum >= 0 && attnum < scanslot->tts_nvalid);
+			Assert(attphysnum >= 0 && attphysnum < scanslot->tts_nvalid);
 			Assert(resultnum >= 0 && resultnum < resultslot->tts_tupleDescriptor->natts);
-			resultslot->tts_values[resultnum] = scanslot->tts_values[attnum];
-			resultslot->tts_isnull[resultnum] = scanslot->tts_isnull[attnum];
+			resultslot->tts_values[resultnum] = scanslot->tts_values[attphysnum];
+			resultslot->tts_isnull[resultnum] = scanslot->tts_isnull[attphysnum];
 
 			EEO_NEXT();
 		}
@@ -1879,25 +1879,25 @@ CheckExprStillValid(ExprState *state, ExprContext *econtext)
 		{
 			case EEOP_INNER_VAR:
 				{
-					int			attnum = op->d.var.attnum;
+					int			attphysnum = op->d.var.attphysnum;
 
-					CheckVarSlotCompatibility(innerslot, attnum + 1, op->d.var.vartype);
+					CheckVarSlotCompatibility(innerslot, attphysnum + 1, op->d.var.vartype);
 					break;
 				}
 
 			case EEOP_OUTER_VAR:
 				{
-					int			attnum = op->d.var.attnum;
+					int			attphysnum = op->d.var.attphysnum;
 
-					CheckVarSlotCompatibility(outerslot, attnum + 1, op->d.var.vartype);
+					CheckVarSlotCompatibility(outerslot, attphysnum + 1, op->d.var.vartype);
 					break;
 				}
 
 			case EEOP_SCAN_VAR:
 				{
-					int			attnum = op->d.var.attnum;
+					int			attphysnum = op->d.var.attphysnum;
 
-					CheckVarSlotCompatibility(scanslot, attnum + 1, op->d.var.vartype);
+					CheckVarSlotCompatibility(scanslot, attphysnum + 1, op->d.var.vartype);
 					break;
 				}
 			default:
@@ -1912,7 +1912,7 @@ CheckExprStillValid(ExprState *state, ExprContext *econtext)
  * since the expression tree has been created.
  */
 static void
-CheckVarSlotCompatibility(TupleTableSlot *slot, int attnum, Oid vartype)
+CheckVarSlotCompatibility(TupleTableSlot *slot, int attphysnum, Oid vartype)
 {
 	/*
 	 * What we have to check for here is the possibility of an attribute
@@ -1931,28 +1931,28 @@ CheckVarSlotCompatibility(TupleTableSlot *slot, int attnum, Oid vartype)
 	 * System attributes don't require checking since their types never
 	 * change.
 	 */
-	if (attnum > 0)
+	if (attphysnum > 0)
 	{
 		TupleDesc	slot_tupdesc = slot->tts_tupleDescriptor;
 		Form_pg_attribute attr;
 
-		if (attnum > slot_tupdesc->natts)	/* should never happen */
+		if (attphysnum > slot_tupdesc->natts)	/* should never happen */
 			elog(ERROR, "attribute number %d exceeds number of columns %d",
-				 attnum, slot_tupdesc->natts);
+				 attphysnum, slot_tupdesc->natts);
 
-		attr = TupleDescAttr(slot_tupdesc, attnum - 1);
+		attr = TupleDescAttr(slot_tupdesc, attphysnum - 1);
 
 		if (attr->attisdropped)
 			ereport(ERROR,
 					(errcode(ERRCODE_UNDEFINED_COLUMN),
 					 errmsg("attribute %d of type %s has been dropped",
-							attnum, format_type_be(slot_tupdesc->tdtypeid))));
+							attphysnum, format_type_be(slot_tupdesc->tdtypeid))));
 
 		if (vartype != attr->atttypid)
 			ereport(ERROR,
 					(errcode(ERRCODE_DATATYPE_MISMATCH),
 					 errmsg("attribute %d of type %s has wrong type",
-							attnum, format_type_be(slot_tupdesc->tdtypeid)),
+							attphysnum, format_type_be(slot_tupdesc->tdtypeid)),
 					 errdetail("Table has type %s, but query expects %s.",
 							   format_type_be(attr->atttypid),
 							   format_type_be(vartype))));
@@ -2078,16 +2078,16 @@ static pg_attribute_always_inline Datum
 ExecJustVarImpl(ExprState *state, TupleTableSlot *slot, bool *isnull)
 {
 	ExprEvalStep *op = &state->steps[1];
-	int			attnum = op->d.var.attnum + 1;
+	int			attphysnum = op->d.var.attphysnum + 1;
 
 	CheckOpSlotCompatibility(&state->steps[0], slot);
 
 	/*
 	 * Since we use slot_getattr(), we don't need to implement the FETCHSOME
-	 * step explicitly, and we also needn't Assert that the attnum is in range
+	 * step explicitly, and we also needn't Assert that the attphysnum is in range
 	 * --- slot_getattr() will take care of any problems.
 	 */
-	return slot_getattr(slot, attnum, isnull);
+	return slot_getattr(slot, attphysnum, isnull);
 }
 
 /* Simple reference to inner Var */
@@ -2116,7 +2116,7 @@ static pg_attribute_always_inline Datum
 ExecJustAssignVarImpl(ExprState *state, TupleTableSlot *inslot, bool *isnull)
 {
 	ExprEvalStep *op = &state->steps[1];
-	int			attnum = op->d.assign_var.attnum + 1;
+	int			attphysnum = op->d.assign_var.attphysnum + 1;
 	int			resultnum = op->d.assign_var.resultnum;
 	TupleTableSlot *outslot = state->resultslot;
 
@@ -2127,13 +2127,13 @@ ExecJustAssignVarImpl(ExprState *state, TupleTableSlot *inslot, bool *isnull)
 	 * at compilation time.
 	 *
 	 * Since we use slot_getattr(), we don't need to implement the FETCHSOME
-	 * step explicitly, and we also needn't Assert that the attnum is in range
+	 * step explicitly, and we also needn't Assert that the attphysnum is in range
 	 * --- slot_getattr() will take care of any problems.  Nonetheless, check
 	 * that resultnum is in range.
 	 */
 	Assert(resultnum >= 0 && resultnum < outslot->tts_tupleDescriptor->natts);
 	outslot->tts_values[resultnum] =
-		slot_getattr(inslot, attnum, &outslot->tts_isnull[resultnum]);
+		slot_getattr(inslot, attphysnum, &outslot->tts_isnull[resultnum]);
 	return 0;
 }
 
@@ -2211,7 +2211,7 @@ static pg_attribute_always_inline Datum
 ExecJustVarVirtImpl(ExprState *state, TupleTableSlot *slot, bool *isnull)
 {
 	ExprEvalStep *op = &state->steps[0];
-	int			attnum = op->d.var.attnum;
+	int			attphysnum = op->d.var.attphysnum;
 
 	/*
 	 * As it is guaranteed that a virtual slot is used, there never is a need
@@ -2221,11 +2221,11 @@ ExecJustVarVirtImpl(ExprState *state, TupleTableSlot *slot, bool *isnull)
 	 */
 	Assert(TTS_IS_VIRTUAL(slot));
 	Assert(TTS_FIXED(slot));
-	Assert(attnum >= 0 && attnum < slot->tts_nvalid);
+	Assert(attphysnum >= 0 && attphysnum < slot->tts_nvalid);
 
-	*isnull = slot->tts_isnull[attnum];
+	*isnull = slot->tts_isnull[attphysnum];
 
-	return slot->tts_values[attnum];
+	return slot->tts_values[attphysnum];
 }
 
 /* Like ExecJustInnerVar, optimized for virtual slots */
@@ -2254,7 +2254,7 @@ static pg_attribute_always_inline Datum
 ExecJustAssignVarVirtImpl(ExprState *state, TupleTableSlot *inslot, bool *isnull)
 {
 	ExprEvalStep *op = &state->steps[0];
-	int			attnum = op->d.assign_var.attnum;
+	int			attphysnum = op->d.assign_var.attphysnum;
 	int			resultnum = op->d.assign_var.resultnum;
 	TupleTableSlot *outslot = state->resultslot;
 
@@ -2262,11 +2262,11 @@ ExecJustAssignVarVirtImpl(ExprState *state, TupleTableSlot *inslot, bool *isnull
 
 	Assert(TTS_IS_VIRTUAL(inslot));
 	Assert(TTS_FIXED(inslot));
-	Assert(attnum >= 0 && attnum < inslot->tts_nvalid);
+	Assert(attphysnum >= 0 && attphysnum < inslot->tts_nvalid);
 	Assert(resultnum >= 0 && resultnum < outslot->tts_tupleDescriptor->natts);
 
-	outslot->tts_values[resultnum] = inslot->tts_values[attnum];
-	outslot->tts_isnull[resultnum] = inslot->tts_isnull[attnum];
+	outslot->tts_values[resultnum] = inslot->tts_values[attphysnum];
+	outslot->tts_isnull[resultnum] = inslot->tts_isnull[attphysnum];
 
 	return 0;
 }
@@ -4036,11 +4036,11 @@ ExecEvalGroupingFunc(ExprState *state, ExprEvalStep *op)
 
 	foreach(lc, op->d.grouping_func.clauses)
 	{
-		int			attnum = lfirst_int(lc);
+		int			attphysnum = lfirst_int(lc);
 
 		result <<= 1;
 
-		if (!bms_is_member(attnum, grouped_cols))
+		if (!bms_is_member(attphysnum, grouped_cols))
 			result |= 1;
 	}
 
@@ -4303,7 +4303,7 @@ ExecEvalSysVar(ExprState *state, ExprEvalStep *op, ExprContext *econtext,
 
 	/* slot_getsysattr has sufficient defenses against bad attnums */
 	d = slot_getsysattr(slot,
-						op->d.var.attnum,
+						op->d.var.attphysnum,
 						op->resnull);
 	*op->resvalue = d;
 	/* this ought to be unreachable, but it's cheap enough to check */
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index ef2fd46092..045c25e634 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -2264,9 +2264,9 @@ ExecBuildSlotValueDescription(Oid reloid,
 			 * for the column.  If not, omit this column from the error
 			 * message.
 			 */
-			aclresult = pg_attribute_aclcheck(reloid, att->attnum,
+			aclresult = pg_attribute_aclcheck(reloid, att->attphysnum,
 											  GetUserId(), ACL_SELECT);
-			if (bms_is_member(att->attnum - FirstLowInvalidHeapAttributeNumber,
+			if (bms_is_member(att->attphysnum - FirstLowInvalidHeapAttributeNumber,
 							  modifiedCols) || aclresult == ACLCHECK_OK)
 			{
 				column_perm = any_perm = true;
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
index e03ea27299..507212a9a8 100644
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -1471,15 +1471,15 @@ ExecBuildSlotPartitionKeyDescription(Relation rel,
 		 */
 		for (i = 0; i < partnatts; i++)
 		{
-			AttrNumber	attnum = get_partition_col_attnum(key, i);
+			AttrNumber	attphysnum = get_partition_col_attnum(key, i);
 
 			/*
 			 * If this partition key column is an expression, we return no
 			 * detail rather than try to figure out what column(s) the
 			 * expression includes and if the user has SELECT rights on them.
 			 */
-			if (attnum == InvalidAttrNumber ||
-				pg_attribute_aclcheck(relid, attnum, GetUserId(),
+			if (attphysnum == InvalidAttrNumber ||
+				pg_attribute_aclcheck(relid, attphysnum, GetUserId(),
 									  ACL_SELECT) != ACLCHECK_OK)
 				return NULL;
 		}
diff --git a/src/backend/executor/execTuples.c b/src/backend/executor/execTuples.c
index 06ac253ea0..c94f45491f 100644
--- a/src/backend/executor/execTuples.c
+++ b/src/backend/executor/execTuples.c
@@ -137,7 +137,7 @@ tts_virtual_getsomeattrs(TupleTableSlot *slot, int natts)
  * here, but provide a user-friendly message if we do.
  */
 static Datum
-tts_virtual_getsysattr(TupleTableSlot *slot, int attnum, bool *isnull)
+tts_virtual_getsysattr(TupleTableSlot *slot, int attphysnum, bool *isnull)
 {
 	Assert(!TTS_EMPTY(slot));
 
@@ -337,7 +337,7 @@ tts_heap_getsomeattrs(TupleTableSlot *slot, int natts)
 }
 
 static Datum
-tts_heap_getsysattr(TupleTableSlot *slot, int attnum, bool *isnull)
+tts_heap_getsysattr(TupleTableSlot *slot, int attphysnum, bool *isnull)
 {
 	HeapTupleTableSlot *hslot = (HeapTupleTableSlot *) slot;
 
@@ -352,7 +352,7 @@ tts_heap_getsysattr(TupleTableSlot *slot, int attnum, bool *isnull)
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot retrieve a system column in this context")));
 
-	return heap_getsysattr(hslot->tuple, attnum,
+	return heap_getsysattr(hslot->tuple, attphysnum,
 						   slot->tts_tupleDescriptor, isnull);
 }
 
@@ -512,7 +512,7 @@ tts_minimal_getsomeattrs(TupleTableSlot *slot, int natts)
 }
 
 static Datum
-tts_minimal_getsysattr(TupleTableSlot *slot, int attnum, bool *isnull)
+tts_minimal_getsysattr(TupleTableSlot *slot, int attphysnum, bool *isnull)
 {
 	Assert(!TTS_EMPTY(slot));
 
@@ -696,7 +696,7 @@ tts_buffer_heap_getsomeattrs(TupleTableSlot *slot, int natts)
 }
 
 static Datum
-tts_buffer_heap_getsysattr(TupleTableSlot *slot, int attnum, bool *isnull)
+tts_buffer_heap_getsysattr(TupleTableSlot *slot, int attphysnum, bool *isnull)
 {
 	BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot;
 
@@ -711,7 +711,7 @@ tts_buffer_heap_getsysattr(TupleTableSlot *slot, int attnum, bool *isnull)
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot retrieve a system column in this context")));
 
-	return heap_getsysattr(bslot->base.tuple, attnum,
+	return heap_getsysattr(bslot->base.tuple, attphysnum,
 						   slot->tts_tupleDescriptor, isnull);
 }
 
@@ -930,7 +930,7 @@ slot_deform_heap_tuple(TupleTableSlot *slot, HeapTuple tuple, uint32 *offp,
 	bool	   *isnull = slot->tts_isnull;
 	HeapTupleHeader tup = tuple->t_data;
 	bool		hasnulls = HeapTupleHasNulls(tuple);
-	int			attnum;
+	int			attphysnum;
 	char	   *tp;				/* ptr to tuple data */
 	uint32		off;			/* offset in tuple data */
 	bits8	   *bp = tup->t_bits;	/* ptr to null bitmap in tuple */
@@ -943,8 +943,8 @@ slot_deform_heap_tuple(TupleTableSlot *slot, HeapTuple tuple, uint32 *offp,
 	 * Check whether the first call for this tuple, and initialize or restore
 	 * loop state.
 	 */
-	attnum = slot->tts_nvalid;
-	if (attnum == 0)
+	attphysnum = slot->tts_nvalid;
+	if (attphysnum == 0)
 	{
 		/* Start from the first attribute */
 		off = 0;
@@ -959,19 +959,19 @@ slot_deform_heap_tuple(TupleTableSlot *slot, HeapTuple tuple, uint32 *offp,
 
 	tp = (char *) tup + tup->t_hoff;
 
-	for (; attnum < natts; attnum++)
+	for (; attphysnum < natts; attphysnum++)
 	{
-		Form_pg_attribute thisatt = TupleDescAttr(tupleDesc, attnum);
+		Form_pg_attribute thisatt = TupleDescAttr(tupleDesc, attphysnum);
 
-		if (hasnulls && att_isnull(attnum, bp))
+		if (hasnulls && att_isnull(attphysnum, bp))
 		{
-			values[attnum] = (Datum) 0;
-			isnull[attnum] = true;
+			values[attphysnum] = (Datum) 0;
+			isnull[attphysnum] = true;
 			slow = true;		/* can't use attcacheoff anymore */
 			continue;
 		}
 
-		isnull[attnum] = false;
+		isnull[attphysnum] = false;
 
 		if (!slow && thisatt->attcacheoff >= 0)
 			off = thisatt->attcacheoff;
@@ -1002,7 +1002,7 @@ slot_deform_heap_tuple(TupleTableSlot *slot, HeapTuple tuple, uint32 *offp,
 				thisatt->attcacheoff = off;
 		}
 
-		values[attnum] = fetchatt(thisatt, tp + off);
+		values[attphysnum] = fetchatt(thisatt, tp + off);
 
 		off = att_addlength_pointer(off, thisatt->attlen, tp + off);
 
@@ -1013,7 +1013,7 @@ slot_deform_heap_tuple(TupleTableSlot *slot, HeapTuple tuple, uint32 *offp,
 	/*
 	 * Save state for next execution
 	 */
-	slot->tts_nvalid = attnum;
+	slot->tts_nvalid = attphysnum;
 	*offp = off;
 	if (slow)
 		slot->tts_flags |= TTS_FLAG_SLOW;
@@ -1899,26 +1899,26 @@ slot_getmissingattrs(TupleTableSlot *slot, int startAttNum, int lastAttNum)
  * slot_getsomeattrs_int - workhorse for slot_getsomeattrs()
  */
 void
-slot_getsomeattrs_int(TupleTableSlot *slot, int attnum)
+slot_getsomeattrs_int(TupleTableSlot *slot, int attphysnum)
 {
 	/* Check for caller errors */
-	Assert(slot->tts_nvalid < attnum);	/* checked in slot_getsomeattrs */
-	Assert(attnum > 0);
+	Assert(slot->tts_nvalid < attphysnum);	/* checked in slot_getsomeattrs */
+	Assert(attphysnum > 0);
 
-	if (unlikely(attnum > slot->tts_tupleDescriptor->natts))
-		elog(ERROR, "invalid attribute number %d", attnum);
+	if (unlikely(attphysnum > slot->tts_tupleDescriptor->natts))
+		elog(ERROR, "invalid attribute number %d", attphysnum);
 
 	/* Fetch as many attributes as possible from the underlying tuple. */
-	slot->tts_ops->getsomeattrs(slot, attnum);
+	slot->tts_ops->getsomeattrs(slot, attphysnum);
 
 	/*
 	 * If the underlying tuple doesn't have enough attributes, tuple
 	 * descriptor must have the missing attributes.
 	 */
-	if (unlikely(slot->tts_nvalid < attnum))
+	if (unlikely(slot->tts_nvalid < attphysnum))
 	{
-		slot_getmissingattrs(slot, slot->tts_nvalid, attnum);
-		slot->tts_nvalid = attnum;
+		slot_getmissingattrs(slot, slot->tts_nvalid, attphysnum);
+		slot->tts_nvalid = attphysnum;
 	}
 }
 
diff --git a/src/backend/executor/execUtils.c b/src/backend/executor/execUtils.c
index 9df1f81ea8..c5caa4e20b 100644
--- a/src/backend/executor/execUtils.c
+++ b/src/backend/executor/execUtils.c
@@ -1054,7 +1054,7 @@ GetAttributeByName(HeapTupleHeader tuple, const char *attname, bool *isNull)
 
 		if (namestrcmp(&(att->attname), attname) == 0)
 		{
-			attrno = att->attnum;
+			attrno = att->attphysnum;
 			break;
 		}
 	}
diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c
index 139b2bd5f9..c94b3ca7cd 100644
--- a/src/backend/executor/nodeAgg.c
+++ b/src/backend/executor/nodeAgg.c
@@ -1269,10 +1269,10 @@ prepare_projection_slot(AggState *aggstate, TupleTableSlot *slot, int currentSet
 
 			foreach(lc, aggstate->all_grouped_cols)
 			{
-				int			attnum = lfirst_int(lc);
+				int			attphysnum = lfirst_int(lc);
 
-				if (!bms_is_member(attnum, grouped_cols))
-					slot->tts_isnull[attnum - 1] = true;
+				if (!bms_is_member(attphysnum, grouped_cols))
+					slot->tts_isnull[attphysnum - 1] = true;
 			}
 		}
 	}
@@ -1595,10 +1595,10 @@ find_hash_columns(AggState *aggstate)
 
 			foreach(lc, aggstate->all_grouped_cols)
 			{
-				int			attnum = lfirst_int(lc);
+				int			attphysnum = lfirst_int(lc);
 
-				if (!bms_is_member(attnum, grouped_cols))
-					colnos = bms_del_member(colnos, attnum);
+				if (!bms_is_member(attphysnum, grouped_cols))
+					colnos = bms_del_member(colnos, attphysnum);
 			}
 		}
 
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 29bc26669b..bdc61e8925 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -1101,7 +1101,7 @@ SPI_returntuple(HeapTuple tuple, TupleDesc tupdesc)
 }
 
 HeapTuple
-SPI_modifytuple(Relation rel, HeapTuple tuple, int natts, int *attnum,
+SPI_modifytuple(Relation rel, HeapTuple tuple, int natts, int *attphysnum,
 				Datum *Values, const char *Nulls)
 {
 	MemoryContext oldcxt;
@@ -1111,7 +1111,7 @@ SPI_modifytuple(Relation rel, HeapTuple tuple, int natts, int *attnum,
 	bool	   *n;
 	int			i;
 
-	if (rel == NULL || tuple == NULL || natts < 0 || attnum == NULL || Values == NULL)
+	if (rel == NULL || tuple == NULL || natts < 0 || attphysnum == NULL || Values == NULL)
 	{
 		SPI_result = SPI_ERROR_ARGUMENT;
 		return NULL;
@@ -1137,13 +1137,13 @@ SPI_modifytuple(Relation rel, HeapTuple tuple, int natts, int *attnum,
 	/* replace values and nulls */
 	for (i = 0; i < natts; i++)
 	{
-		if (attnum[i] <= 0 || attnum[i] > numberOfAttributes)
+		if (attphysnum[i] <= 0 || attphysnum[i] > numberOfAttributes)
 			break;
-		v[attnum[i] - 1] = Values[i];
-		n[attnum[i] - 1] = (Nulls && Nulls[i] == 'n');
+		v[attphysnum[i] - 1] = Values[i];
+		n[attphysnum[i] - 1] = (Nulls && Nulls[i] == 'n');
 	}
 
-	if (i == natts)				/* no errors in *attnum */
+	if (i == natts)				/* no errors in *attphysnum */
 	{
 		mtuple = heap_form_tuple(rel->rd_att, v, n);
 
@@ -1186,7 +1186,7 @@ SPI_fnumber(TupleDesc tupdesc, const char *fname)
 
 	sysatt = SystemAttributeByName(fname);
 	if (sysatt != NULL)
-		return sysatt->attnum;
+		return sysatt->attphysnum;
 
 	/* SPI_ERROR_NOATTRIBUTE is different from all sys column numbers */
 	return SPI_ERROR_NOATTRIBUTE;
diff --git a/src/backend/foreign/foreign.c b/src/backend/foreign/foreign.c
index cf222fc3e9..c064fe50cd 100644
--- a/src/backend/foreign/foreign.c
+++ b/src/backend/foreign/foreign.c
@@ -284,20 +284,20 @@ GetForeignTable(Oid relid)
  * as list of DefElem.
  */
 List *
-GetForeignColumnOptions(Oid relid, AttrNumber attnum)
+GetForeignColumnOptions(Oid relid, AttrNumber attphysnum)
 {
 	List	   *options;
 	HeapTuple	tp;
 	Datum		datum;
 	bool		isnull;
 
-	tp = SearchSysCache2(ATTNUM,
+	tp = SearchSysCache2(ATTPHYSNUM,
 						 ObjectIdGetDatum(relid),
-						 Int16GetDatum(attnum));
+						 Int16GetDatum(attphysnum));
 	if (!HeapTupleIsValid(tp))
 		elog(ERROR, "cache lookup failed for attribute %d of relation %u",
-			 attnum, relid);
-	datum = SysCacheGetAttr(ATTNUM,
+			 attphysnum, relid);
+	datum = SysCacheGetAttr(ATTPHYSNUM,
 							tp,
 							Anum_pg_attribute_attfdwoptions,
 							&isnull);
diff --git a/src/backend/jit/llvm/llvmjit_deform.c b/src/backend/jit/llvm/llvmjit_deform.c
index 661f15272b..67e958a58a 100644
--- a/src/backend/jit/llvm/llvmjit_deform.c
+++ b/src/backend/jit/llvm/llvmjit_deform.c
@@ -87,7 +87,7 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc,
 	/* if true, known_alignment describes definite offset of column */
 	bool		attguaranteedalign = true;
 
-	int			attnum;
+	int			attphysnum;
 
 	/* virtual tuples never need deforming, so don't generate code */
 	if (ops == &TTSOpsVirtual)
@@ -106,9 +106,9 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc,
 	 * Check which columns have to exist, so we don't have to check the row's
 	 * natts unnecessarily.
 	 */
-	for (attnum = 0; attnum < desc->natts; attnum++)
+	for (attphysnum = 0; attphysnum < desc->natts; attphysnum++)
 	{
-		Form_pg_attribute att = TupleDescAttr(desc, attnum);
+		Form_pg_attribute att = TupleDescAttr(desc, attphysnum);
 
 		/*
 		 * If the column is declared NOT NULL then it must be present in every
@@ -124,7 +124,7 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc,
 		if (att->attnotnull &&
 			!att->atthasmissing &&
 			!att->attisdropped)
-			guaranteed_column_number = attnum;
+			guaranteed_column_number = attphysnum;
 	}
 
 	/* Create the signature and function */
@@ -280,20 +280,20 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc,
 	}
 
 	/* build the basic block for each attribute, need them as jump target */
-	for (attnum = 0; attnum < natts; attnum++)
+	for (attphysnum = 0; attphysnum < natts; attphysnum++)
 	{
-		attcheckattnoblocks[attnum] =
-			l_bb_append_v(v_deform_fn, "block.attr.%d.attcheckattno", attnum);
-		attstartblocks[attnum] =
-			l_bb_append_v(v_deform_fn, "block.attr.%d.start", attnum);
-		attisnullblocks[attnum] =
-			l_bb_append_v(v_deform_fn, "block.attr.%d.attisnull", attnum);
-		attcheckalignblocks[attnum] =
-			l_bb_append_v(v_deform_fn, "block.attr.%d.attcheckalign", attnum);
-		attalignblocks[attnum] =
-			l_bb_append_v(v_deform_fn, "block.attr.%d.align", attnum);
-		attstoreblocks[attnum] =
-			l_bb_append_v(v_deform_fn, "block.attr.%d.store", attnum);
+		attcheckattnoblocks[attphysnum] =
+			l_bb_append_v(v_deform_fn, "block.attr.%d.attcheckattno", attphysnum);
+		attstartblocks[attphysnum] =
+			l_bb_append_v(v_deform_fn, "block.attr.%d.start", attphysnum);
+		attisnullblocks[attphysnum] =
+			l_bb_append_v(v_deform_fn, "block.attr.%d.attisnull", attphysnum);
+		attcheckalignblocks[attphysnum] =
+			l_bb_append_v(v_deform_fn, "block.attr.%d.attcheckalign", attphysnum);
+		attalignblocks[attphysnum] =
+			l_bb_append_v(v_deform_fn, "block.attr.%d.align", attphysnum);
+		attstoreblocks[attphysnum] =
+			l_bb_append_v(v_deform_fn, "block.attr.%d.store", attphysnum);
 	}
 
 	/*
@@ -350,11 +350,11 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc,
 		LLVMValueRef v_switch = LLVMBuildSwitch(b, v_nvalid,
 												b_dead, natts);
 
-		for (attnum = 0; attnum < natts; attnum++)
+		for (attphysnum = 0; attphysnum < natts; attphysnum++)
 		{
-			LLVMValueRef v_attno = l_int16_const(attnum);
+			LLVMValueRef v_attno = l_int16_const(attphysnum);
 
-			LLVMAddCase(v_switch, v_attno, attcheckattnoblocks[attnum]);
+			LLVMAddCase(v_switch, v_attno, attcheckattnoblocks[attphysnum]);
 		}
 	}
 	else
@@ -370,23 +370,23 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc,
 	 * Iterate over each attribute that needs to be deformed, build code to
 	 * deform it.
 	 */
-	for (attnum = 0; attnum < natts; attnum++)
+	for (attphysnum = 0; attphysnum < natts; attphysnum++)
 	{
-		Form_pg_attribute att = TupleDescAttr(desc, attnum);
+		Form_pg_attribute att = TupleDescAttr(desc, attphysnum);
 		LLVMValueRef v_incby;
 		int			alignto;
-		LLVMValueRef l_attno = l_int16_const(attnum);
+		LLVMValueRef l_attno = l_int16_const(attphysnum);
 		LLVMValueRef v_attdatap;
 		LLVMValueRef v_resultp;
 
 		/* build block checking whether we did all the necessary attributes */
-		LLVMPositionBuilderAtEnd(b, attcheckattnoblocks[attnum]);
+		LLVMPositionBuilderAtEnd(b, attcheckattnoblocks[attphysnum]);
 
 		/*
 		 * If this is the first attribute, slot->tts_nvalid was 0. Therefore
 		 * also reset offset to 0, it may be from a previous execution.
 		 */
-		if (attnum == 0)
+		if (attphysnum == 0)
 		{
 			LLVMBuildStore(b, l_sizet_const(0), v_offp);
 		}
@@ -396,9 +396,9 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc,
 		 * that many columns stored). We can avoid the branch if we know
 		 * there's a subsequent NOT NULL column.
 		 */
-		if (attnum <= guaranteed_column_number)
+		if (attphysnum <= guaranteed_column_number)
 		{
-			LLVMBuildBr(b, attstartblocks[attnum]);
+			LLVMBuildBr(b, attstartblocks[attphysnum]);
 		}
 		else
 		{
@@ -408,9 +408,9 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc,
 									 l_attno,
 									 v_maxatt,
 									 "heap_natts");
-			LLVMBuildCondBr(b, v_islast, b_out, attstartblocks[attnum]);
+			LLVMBuildCondBr(b, v_islast, b_out, attstartblocks[attphysnum]);
 		}
-		LLVMPositionBuilderAtEnd(b, attstartblocks[attnum]);
+		LLVMPositionBuilderAtEnd(b, attstartblocks[attphysnum]);
 
 		/*
 		 * Check for nulls if necessary. No need to take missing attributes
@@ -428,16 +428,16 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc,
 			LLVMValueRef v_nullbyte;
 			LLVMValueRef v_nullbit;
 
-			b_ifnotnull = attcheckalignblocks[attnum];
-			b_ifnull = attisnullblocks[attnum];
+			b_ifnotnull = attcheckalignblocks[attphysnum];
+			b_ifnull = attisnullblocks[attphysnum];
 
-			if (attnum + 1 == natts)
+			if (attphysnum + 1 == natts)
 				b_next = b_out;
 			else
-				b_next = attcheckattnoblocks[attnum + 1];
+				b_next = attcheckattnoblocks[attphysnum + 1];
 
-			v_nullbyteno = l_int32_const(attnum >> 3);
-			v_nullbytemask = l_int8_const(1 << ((attnum) & 0x07));
+			v_nullbyteno = l_int32_const(attphysnum >> 3);
+			v_nullbytemask = l_int8_const(1 << ((attphysnum) & 0x07));
 			v_nullbyte = l_load_gep1(b, v_bits, v_nullbyteno, "attnullbyte");
 
 			v_nullbit = LLVMBuildICmp(b,
@@ -467,11 +467,11 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc,
 		else
 		{
 			/* nothing to do */
-			LLVMBuildBr(b, attcheckalignblocks[attnum]);
-			LLVMPositionBuilderAtEnd(b, attisnullblocks[attnum]);
-			LLVMBuildBr(b, attcheckalignblocks[attnum]);
+			LLVMBuildBr(b, attcheckalignblocks[attphysnum]);
+			LLVMPositionBuilderAtEnd(b, attisnullblocks[attphysnum]);
+			LLVMBuildBr(b, attcheckalignblocks[attphysnum]);
 		}
-		LLVMPositionBuilderAtEnd(b, attcheckalignblocks[attnum]);
+		LLVMPositionBuilderAtEnd(b, attcheckalignblocks[attphysnum]);
 
 		/* determine required alignment */
 		if (att->attalign == TYPALIGN_INT)
@@ -527,15 +527,15 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc,
 								  v_possible_padbyte, l_int8_const(0),
 								  "ispadbyte");
 				LLVMBuildCondBr(b, v_ispad,
-								attalignblocks[attnum],
-								attstoreblocks[attnum]);
+								attalignblocks[attphysnum],
+								attstoreblocks[attphysnum]);
 			}
 			else
 			{
-				LLVMBuildBr(b, attalignblocks[attnum]);
+				LLVMBuildBr(b, attalignblocks[attphysnum]);
 			}
 
-			LLVMPositionBuilderAtEnd(b, attalignblocks[attnum]);
+			LLVMPositionBuilderAtEnd(b, attalignblocks[attphysnum]);
 
 			/* translation of alignment code (cf TYPEALIGN()) */
 			{
@@ -567,17 +567,17 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc,
 				known_alignment = TYPEALIGN(alignto, known_alignment);
 			}
 
-			LLVMBuildBr(b, attstoreblocks[attnum]);
-			LLVMPositionBuilderAtEnd(b, attstoreblocks[attnum]);
+			LLVMBuildBr(b, attstoreblocks[attphysnum]);
+			LLVMPositionBuilderAtEnd(b, attstoreblocks[attphysnum]);
 		}
 		else
 		{
-			LLVMPositionBuilderAtEnd(b, attcheckalignblocks[attnum]);
-			LLVMBuildBr(b, attalignblocks[attnum]);
-			LLVMPositionBuilderAtEnd(b, attalignblocks[attnum]);
-			LLVMBuildBr(b, attstoreblocks[attnum]);
+			LLVMPositionBuilderAtEnd(b, attcheckalignblocks[attphysnum]);
+			LLVMBuildBr(b, attalignblocks[attphysnum]);
+			LLVMPositionBuilderAtEnd(b, attalignblocks[attphysnum]);
+			LLVMBuildBr(b, attstoreblocks[attphysnum]);
 		}
-		LLVMPositionBuilderAtEnd(b, attstoreblocks[attnum]);
+		LLVMPositionBuilderAtEnd(b, attstoreblocks[attphysnum]);
 
 		/*
 		 * Store the current offset if known to be constant. That allows LLVM
@@ -720,14 +720,14 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc,
 		 * jump to next block, unless last possible column, or all desired
 		 * (available) attributes have been fetched.
 		 */
-		if (attnum + 1 == natts)
+		if (attphysnum + 1 == natts)
 		{
 			/* jump out */
 			LLVMBuildBr(b, b_out);
 		}
 		else
 		{
-			LLVMBuildBr(b, attcheckattnoblocks[attnum + 1]);
+			LLVMBuildBr(b, attcheckattnoblocks[attphysnum + 1]);
 		}
 	}
 
diff --git a/src/backend/jit/llvm/llvmjit_expr.c b/src/backend/jit/llvm/llvmjit_expr.c
index b6b6512ef1..f12bff8103 100644
--- a/src/backend/jit/llvm/llvmjit_expr.c
+++ b/src/backend/jit/llvm/llvmjit_expr.c
@@ -372,7 +372,7 @@ llvm_compile_expr(ExprState *state)
 						v_nulls = v_scannulls;
 					}
 
-					v_attnum = l_int32_const(op->d.var.attnum);
+					v_attnum = l_int32_const(op->d.var.attphysnum);
 					value = l_load_gep1(b, v_values, v_attnum, "");
 					isnull = l_load_gep1(b, v_nulls, v_attnum, "");
 					LLVMBuildStore(b, value, v_resvaluep);
@@ -438,7 +438,7 @@ llvm_compile_expr(ExprState *state)
 					}
 
 					/* load data */
-					v_attnum = l_int32_const(op->d.assign_var.attnum);
+					v_attnum = l_int32_const(op->d.assign_var.attphysnum);
 					v_value = l_load_gep1(b, v_values, v_attnum, "");
 					v_isnull = l_load_gep1(b, v_nulls, v_attnum, "");
 
diff --git a/src/backend/optimizer/util/appendinfo.c b/src/backend/optimizer/util/appendinfo.c
index 9d4bb47027..ca83ecb997 100644
--- a/src/backend/optimizer/util/appendinfo.c
+++ b/src/backend/optimizer/util/appendinfo.c
@@ -150,7 +150,7 @@ make_inh_translation_list(Relation oldrelation, Relation newrelation,
 			if (!HeapTupleIsValid(newtup))
 				elog(ERROR, "could not find inherited attribute \"%s\" of relation \"%s\"",
 					 attname, RelationGetRelationName(newrelation));
-			new_attno = ((Form_pg_attribute) GETSTRUCT(newtup))->attnum - 1;
+			new_attno = ((Form_pg_attribute) GETSTRUCT(newtup))->attphysnum - 1;
 			Assert(new_attno >= 0 && new_attno < newnatts);
 			ReleaseSysCache(newtup);
 
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 1bcb875507..5ced631957 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -1246,9 +1246,9 @@ count_rowexpr_columns(ParseState *pstate, Node *expr)
 	if (IsA(expr, Var))
 	{
 		Var		   *var = (Var *) expr;
-		AttrNumber	attnum = var->varattno;
+		AttrNumber	attphysnum = var->varattno;
 
-		if (attnum > 0 && var->vartype == RECORDOID)
+		if (attphysnum > 0 && var->vartype == RECORDOID)
 		{
 			RangeTblEntry *rte;
 
@@ -1257,7 +1257,7 @@ count_rowexpr_columns(ParseState *pstate, Node *expr)
 			{
 				/* Subselect-in-FROM: examine sub-select's output expr */
 				TargetEntry *ste = get_tle_by_resno(rte->subquery->targetList,
-													attnum);
+													attphysnum);
 
 				if (ste == NULL || ste->resjunk)
 					return -1;
diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c
index c655d188c7..d1b0080268 100644
--- a/src/backend/parser/parse_clause.c
+++ b/src/backend/parser/parse_clause.c
@@ -257,11 +257,11 @@ extractRemainingColumns(ParseNamespaceColumn *src_nscolumns,
 {
 	int			colcount = 0;
 	Bitmapset  *prevcols;
-	int			attnum;
+	int			attphysnum;
 	ListCell   *lc;
 
 	/*
-	 * While we could just test "list_member_int(*src_colnos, attnum)" to
+	 * While we could just test "list_member_int(*src_colnos, attphysnum)" to
 	 * detect already-merged columns in the loop below, that would be O(N^2)
 	 * for a wide input table.  Instead build a bitmapset of just the merged
 	 * USING columns, which we won't add to within the main loop.
@@ -272,22 +272,22 @@ extractRemainingColumns(ParseNamespaceColumn *src_nscolumns,
 		prevcols = bms_add_member(prevcols, lfirst_int(lc));
 	}
 
-	attnum = 0;
+	attphysnum = 0;
 	foreach(lc, src_colnames)
 	{
 		char	   *colname = strVal(lfirst(lc));
 
-		attnum++;
+		attphysnum++;
 		/* Non-dropped and not already merged? */
-		if (colname[0] != '\0' && !bms_is_member(attnum, prevcols))
+		if (colname[0] != '\0' && !bms_is_member(attphysnum, prevcols))
 		{
 			/* Yes, so emit it as next output column */
-			*src_colnos = lappend_int(*src_colnos, attnum);
+			*src_colnos = lappend_int(*src_colnos, attphysnum);
 			*res_colnames = lappend(*res_colnames, lfirst(lc));
 			*res_colvars = lappend(*res_colvars,
-								   buildVarFromNSColumn(src_nscolumns + attnum - 1));
+								   buildVarFromNSColumn(src_nscolumns + attphysnum - 1));
 			/* Copy the input relation's nscolumn data for this column */
-			res_nscolumns[colcount] = src_nscolumns[attnum - 1];
+			res_nscolumns[colcount] = src_nscolumns[attphysnum - 1];
 			colcount++;
 		}
 	}
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index 926dcbf30e..27c3abb7ec 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -566,7 +566,7 @@ GetCTEForRTE(ParseState *pstate, RangeTblEntry *rte, int rtelevelsup)
 static void
 updateFuzzyAttrMatchState(int fuzzy_rte_penalty,
 						  FuzzyAttrMatchState *fuzzystate, RangeTblEntry *rte,
-						  const char *actual, const char *match, int attnum)
+						  const char *actual, const char *match, int attphysnum)
 {
 	int			columndistance;
 	int			matchlen;
@@ -613,7 +613,7 @@ updateFuzzyAttrMatchState(int fuzzy_rte_penalty,
 		/* Store new lowest observed distance for RTE */
 		fuzzystate->distance = columndistance;
 		fuzzystate->rfirst = rte;
-		fuzzystate->first = attnum;
+		fuzzystate->first = attphysnum;
 		fuzzystate->rsecond = NULL;
 		fuzzystate->second = InvalidAttrNumber;
 	}
@@ -640,7 +640,7 @@ updateFuzzyAttrMatchState(int fuzzy_rte_penalty,
 		{
 			/* Record as provisional second match for RTE */
 			fuzzystate->rsecond = rte;
-			fuzzystate->second = attnum;
+			fuzzystate->second = attphysnum;
 		}
 		else if (fuzzystate->distance <= MAX_FUZZY_DISTANCE)
 		{
@@ -650,7 +650,7 @@ updateFuzzyAttrMatchState(int fuzzy_rte_penalty,
 			 * than being associated with a real match)
 			 */
 			fuzzystate->rfirst = rte;
-			fuzzystate->first = attnum;
+			fuzzystate->first = attphysnum;
 		}
 	}
 }
@@ -669,23 +669,23 @@ scanNSItemForColumn(ParseState *pstate, ParseNamespaceItem *nsitem,
 					int sublevels_up, const char *colname, int location)
 {
 	RangeTblEntry *rte = nsitem->p_rte;
-	int			attnum;
+	int			attphysnum;
 	Var		   *var;
 
 	/*
 	 * Scan the nsitem's column names (or aliases) for a match.  Complain if
 	 * multiple matches.
 	 */
-	attnum = scanRTEForColumn(pstate, rte, nsitem->p_names,
+	attphysnum = scanRTEForColumn(pstate, rte, nsitem->p_names,
 							  colname, location,
 							  0, NULL);
 
-	if (attnum == InvalidAttrNumber)
+	if (attphysnum == InvalidAttrNumber)
 		return NULL;			/* Return NULL if no match */
 
 	/* In constraint check, no system column is allowed except tableOid */
 	if (pstate->p_expr_kind == EXPR_KIND_CHECK_CONSTRAINT &&
-		attnum < InvalidAttrNumber && attnum != TableOidAttributeNumber)
+		attphysnum < InvalidAttrNumber && attphysnum != TableOidAttributeNumber)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 				 errmsg("system column \"%s\" reference in check constraint is invalid",
@@ -694,7 +694,7 @@ scanNSItemForColumn(ParseState *pstate, ParseNamespaceItem *nsitem,
 
 	/* In generated column, no system column is allowed except tableOid */
 	if (pstate->p_expr_kind == EXPR_KIND_GENERATED_COLUMN &&
-		attnum < InvalidAttrNumber && attnum != TableOidAttributeNumber)
+		attphysnum < InvalidAttrNumber && attphysnum != TableOidAttributeNumber)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 				 errmsg("cannot use system column \"%s\" in column generation expression",
@@ -705,7 +705,7 @@ scanNSItemForColumn(ParseState *pstate, ParseNamespaceItem *nsitem,
 	 * In a MERGE WHEN condition, no system column is allowed except tableOid
 	 */
 	if (pstate->p_expr_kind == EXPR_KIND_MERGE_WHEN &&
-		attnum < InvalidAttrNumber && attnum != TableOidAttributeNumber)
+		attphysnum < InvalidAttrNumber && attphysnum != TableOidAttributeNumber)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 				 errmsg("cannot use system column \"%s\" in MERGE WHEN condition",
@@ -713,10 +713,10 @@ scanNSItemForColumn(ParseState *pstate, ParseNamespaceItem *nsitem,
 				 parser_errposition(pstate, location)));
 
 	/* Found a valid match, so build a Var */
-	if (attnum > InvalidAttrNumber)
+	if (attphysnum > InvalidAttrNumber)
 	{
 		/* Get attribute data from the ParseNamespaceColumn array */
-		ParseNamespaceColumn *nscol = &nsitem->p_nscolumns[attnum - 1];
+		ParseNamespaceColumn *nscol = &nsitem->p_nscolumns[attphysnum - 1];
 
 		/* Complain if dropped column.  See notes in scanRTEForColumn. */
 		if (nscol->p_varno == 0)
@@ -741,9 +741,9 @@ scanNSItemForColumn(ParseState *pstate, ParseNamespaceItem *nsitem,
 		/* System column, so use predetermined type data */
 		const FormData_pg_attribute *sysatt;
 
-		sysatt = SystemAttributeDefinition(attnum);
+		sysatt = SystemAttributeDefinition(attphysnum);
 		var = makeVar(nsitem->p_rtindex,
-					  attnum,
+					  attphysnum,
 					  sysatt->atttypid,
 					  sysatt->atttypmod,
 					  sysatt->attcollation,
@@ -760,7 +760,7 @@ scanNSItemForColumn(ParseState *pstate, ParseNamespaceItem *nsitem,
 /*
  * scanRTEForColumn
  *	  Search the column names of a single RTE for the given name.
- *	  If found, return the attnum (possibly negative, for a system column);
+ *	  If found, return the attphysnum (possibly negative, for a system column);
  *	  else return InvalidAttrNumber.
  *	  If the name proves ambiguous within this RTE, raise error.
  *
@@ -789,7 +789,7 @@ scanRTEForColumn(ParseState *pstate, RangeTblEntry *rte,
 				 FuzzyAttrMatchState *fuzzystate)
 {
 	int			result = InvalidAttrNumber;
-	int			attnum = 0;
+	int			attphysnum = 0;
 	ListCell   *c;
 
 	/*
@@ -809,7 +809,7 @@ scanRTEForColumn(ParseState *pstate, RangeTblEntry *rte,
 	{
 		const char *attcolname = strVal(lfirst(c));
 
-		attnum++;
+		attphysnum++;
 		if (strcmp(attcolname, colname) == 0)
 		{
 			if (result)
@@ -818,13 +818,13 @@ scanRTEForColumn(ParseState *pstate, RangeTblEntry *rte,
 						 errmsg("column reference \"%s\" is ambiguous",
 								colname),
 						 parser_errposition(pstate, location)));
-			result = attnum;
+			result = attphysnum;
 		}
 
 		/* Update fuzzy match state, if provided. */
 		if (fuzzystate != NULL)
 			updateFuzzyAttrMatchState(fuzzy_rte_penalty, fuzzystate,
-									  rte, attcolname, colname, attnum);
+									  rte, attcolname, colname, attphysnum);
 	}
 
 	/*
@@ -843,14 +843,14 @@ scanRTEForColumn(ParseState *pstate, RangeTblEntry *rte,
 		rte->relkind != RELKIND_COMPOSITE_TYPE)
 	{
 		/* quick check to see if name could be a system column */
-		attnum = specialAttNum(colname);
-		if (attnum != InvalidAttrNumber)
+		attphysnum = specialAttNum(colname);
+		if (attphysnum != InvalidAttrNumber)
 		{
 			/* now check to see if column actually is defined */
-			if (SearchSysCacheExists2(ATTNUM,
+			if (SearchSysCacheExists2(ATTPHYSNUM,
 									  ObjectIdGetDatum(rte->relid),
-									  Int16GetDatum(attnum)))
-				result = attnum;
+									  Int16GetDatum(attphysnum)))
+				result = attphysnum;
 		}
 	}
 
@@ -1023,7 +1023,7 @@ markRTEForSelectPriv(ParseState *pstate, int rtindex, AttrNumber col)
 	{
 		/* Make sure the rel as a whole is marked for SELECT access */
 		rte->requiredPerms |= ACL_SELECT;
-		/* Must offset the attnum to fit in a bitmapset */
+		/* Must offset the attphysnum to fit in a bitmapset */
 		rte->selectedCols = bms_add_member(rte->selectedCols,
 										   col - FirstLowInvalidHeapAttributeNumber);
 	}
@@ -2746,7 +2746,7 @@ expandRTE(RangeTblEntry *rte, int rtindex, int sublevels_up,
 							ListCell   *l1;
 							ListCell   *l2;
 							ListCell   *l3;
-							int			attnum = atts_done;
+							int			attphysnum = atts_done;
 
 							forthree(l1, rtfunc->funccoltypes,
 									 l2, rtfunc->funccoltypmods,
@@ -2757,9 +2757,9 @@ expandRTE(RangeTblEntry *rte, int rtindex, int sublevels_up,
 								Oid			attrcollation = lfirst_oid(l3);
 								Var		   *varnode;
 
-								attnum++;
+								attphysnum++;
 								varnode = makeVar(rtindex,
-												  attnum,
+												  attphysnum,
 												  attrtype,
 												  attrtypmod,
 												  attrcollation,
@@ -3181,21 +3181,21 @@ expandNSItemAttrs(ParseState *pstate, ParseNamespaceItem *nsitem,
  * In particular, it will work on an RTE for a subselect or join, whereas
  * get_attname() only works on real relations.
  *
- * "*" is returned if the given attnum is InvalidAttrNumber --- this case
+ * "*" is returned if the given attphysnum is InvalidAttrNumber --- this case
  * occurs when a Var represents a whole tuple of a relation.
  */
 char *
-get_rte_attribute_name(RangeTblEntry *rte, AttrNumber attnum)
+get_rte_attribute_name(RangeTblEntry *rte, AttrNumber attphysnum)
 {
-	if (attnum == InvalidAttrNumber)
+	if (attphysnum == InvalidAttrNumber)
 		return "*";
 
 	/*
 	 * If there is a user-written column alias, use it.
 	 */
 	if (rte->alias &&
-		attnum > 0 && attnum <= list_length(rte->alias->colnames))
-		return strVal(list_nth(rte->alias->colnames, attnum - 1));
+		attphysnum > 0 && attphysnum <= list_length(rte->alias->colnames))
+		return strVal(list_nth(rte->alias->colnames, attphysnum - 1));
 
 	/*
 	 * If the RTE is a relation, go to the system catalogs not the
@@ -3204,17 +3204,17 @@ get_rte_attribute_name(RangeTblEntry *rte, AttrNumber attnum)
 	 * built (which can easily happen for rules).
 	 */
 	if (rte->rtekind == RTE_RELATION)
-		return get_attname(rte->relid, attnum, false);
+		return get_attname(rte->relid, attphysnum, false);
 
 	/*
 	 * Otherwise use the column name from eref.  There should always be one.
 	 */
-	if (attnum > 0 && attnum <= list_length(rte->eref->colnames))
-		return strVal(list_nth(rte->eref->colnames, attnum - 1));
+	if (attphysnum > 0 && attphysnum <= list_length(rte->eref->colnames))
+		return strVal(list_nth(rte->eref->colnames, attphysnum - 1));
 
-	/* else caller gave us a bogus attnum */
-	elog(ERROR, "invalid attnum %d for rangetable entry %s",
-		 attnum, rte->eref->aliasname);
+	/* else caller gave us a bogus attphysnum */
+	elog(ERROR, "invalid attphysnum %d for rangetable entry %s",
+		 attphysnum, rte->eref->aliasname);
 	return NULL;				/* keep compiler quiet */
 }
 
@@ -3223,7 +3223,7 @@ get_rte_attribute_name(RangeTblEntry *rte, AttrNumber attnum)
  *		Check whether attempted attribute ref is to a dropped column
  */
 bool
-get_rte_attribute_is_dropped(RangeTblEntry *rte, AttrNumber attnum)
+get_rte_attribute_is_dropped(RangeTblEntry *rte, AttrNumber attphysnum)
 {
 	bool		result;
 
@@ -3237,12 +3237,12 @@ get_rte_attribute_is_dropped(RangeTblEntry *rte, AttrNumber attnum)
 				HeapTuple	tp;
 				Form_pg_attribute att_tup;
 
-				tp = SearchSysCache2(ATTNUM,
+				tp = SearchSysCache2(ATTPHYSNUM,
 									 ObjectIdGetDatum(rte->relid),
-									 Int16GetDatum(attnum));
+									 Int16GetDatum(attphysnum));
 				if (!HeapTupleIsValid(tp))	/* shouldn't happen */
 					elog(ERROR, "cache lookup failed for attribute %d of relation %u",
-						 attnum, rte->relid);
+						 attphysnum, rte->relid);
 				att_tup = (Form_pg_attribute) GETSTRUCT(tp);
 				result = att_tup->attisdropped;
 				ReleaseSysCache(tp);
@@ -3262,10 +3262,10 @@ get_rte_attribute_is_dropped(RangeTblEntry *rte, AttrNumber attnum)
 		case RTE_NAMEDTUPLESTORE:
 			{
 				/* Check dropped-ness by testing for valid coltype */
-				if (attnum <= 0 ||
-					attnum > list_length(rte->coltypes))
-					elog(ERROR, "invalid varattno %d", attnum);
-				result = !OidIsValid((list_nth_oid(rte->coltypes, attnum - 1)));
+				if (attphysnum <= 0 ||
+					attphysnum > list_length(rte->coltypes))
+					elog(ERROR, "invalid varattno %d", attphysnum);
+				result = !OidIsValid((list_nth_oid(rte->coltypes, attphysnum - 1)));
 			}
 			break;
 		case RTE_JOIN:
@@ -3279,10 +3279,10 @@ get_rte_attribute_is_dropped(RangeTblEntry *rte, AttrNumber attnum)
 				 */
 				Var		   *aliasvar;
 
-				if (attnum <= 0 ||
-					attnum > list_length(rte->joinaliasvars))
-					elog(ERROR, "invalid varattno %d", attnum);
-				aliasvar = (Var *) list_nth(rte->joinaliasvars, attnum - 1);
+				if (attphysnum <= 0 ||
+					attphysnum > list_length(rte->joinaliasvars))
+					elog(ERROR, "invalid varattno %d", attphysnum);
+				aliasvar = (Var *) list_nth(rte->joinaliasvars, attphysnum - 1);
 
 				result = (aliasvar == NULL);
 			}
@@ -3304,8 +3304,8 @@ get_rte_attribute_is_dropped(RangeTblEntry *rte, AttrNumber attnum)
 				{
 					RangeTblFunction *rtfunc = (RangeTblFunction *) lfirst(lc);
 
-					if (attnum > atts_done &&
-						attnum <= atts_done + rtfunc->funccolcount)
+					if (attphysnum > atts_done &&
+						attphysnum <= atts_done + rtfunc->funccolcount)
 					{
 						TupleDesc	tupdesc;
 
@@ -3317,9 +3317,9 @@ get_rte_attribute_is_dropped(RangeTblEntry *rte, AttrNumber attnum)
 							Form_pg_attribute att_tup;
 
 							Assert(tupdesc);
-							Assert(attnum - atts_done <= tupdesc->natts);
+							Assert(attphysnum - atts_done <= tupdesc->natts);
 							att_tup = TupleDescAttr(tupdesc,
-													attnum - atts_done - 1);
+													attphysnum - atts_done - 1);
 							return att_tup->attisdropped;
 						}
 						/* Otherwise, it can't have any dropped columns */
@@ -3329,14 +3329,14 @@ get_rte_attribute_is_dropped(RangeTblEntry *rte, AttrNumber attnum)
 				}
 
 				/* If we get here, must be looking for the ordinality column */
-				if (rte->funcordinality && attnum == atts_done + 1)
+				if (rte->funcordinality && attphysnum == atts_done + 1)
 					return false;
 
 				/* this probably can't happen ... */
 				ereport(ERROR,
 						(errcode(ERRCODE_UNDEFINED_COLUMN),
 						 errmsg("column %d of relation \"%s\" does not exist",
-								attnum,
+								attphysnum,
 								rte->eref->aliasname)));
 				result = false; /* keep compiler quiet */
 			}
@@ -3346,7 +3346,7 @@ get_rte_attribute_is_dropped(RangeTblEntry *rte, AttrNumber attnum)
 			ereport(ERROR,
 					(errcode(ERRCODE_UNDEFINED_COLUMN),
 					 errmsg("column %d of relation \"%s\" does not exist",
-							attnum,
+							attphysnum,
 							rte->eref->aliasname)));
 			result = false;		/* keep compiler quiet */
 			break;
@@ -3402,12 +3402,12 @@ get_parse_rowmark(Query *qry, Index rtindex)
 }
 
 /*
- *	given relation and att name, return attnum of variable
+ *	given relation and att name, return attphysnum of variable
  *
  *	Returns InvalidAttrNumber if the attr doesn't exist (or is dropped).
  *
  *	This should only be used if the relation is already
- *	table_open()'ed.  Use the cache version get_attnum()
+ *	table_open()'ed.  Use the cache version get_attphysnum()
  *	for access to non-opened relations.
  */
 int
@@ -3448,7 +3448,7 @@ specialAttNum(const char *attname)
 
 	sysatt = SystemAttributeByName(attname);
 	if (sysatt != NULL)
-		return sysatt->attnum;
+		return sysatt->attphysnum;
 	return InvalidAttrNumber;
 }
 
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 2a1d44b813..cff1cda48d 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -347,31 +347,31 @@ markTargetListOrigin(ParseState *pstate, TargetEntry *tle,
 {
 	int			netlevelsup;
 	RangeTblEntry *rte;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 
 	if (var == NULL || !IsA(var, Var))
 		return;
 	netlevelsup = var->varlevelsup + levelsup;
 	rte = GetRTEByRangeTablePosn(pstate, var->varno, netlevelsup);
-	attnum = var->varattno;
+	attphysnum = var->varattno;
 
 	switch (rte->rtekind)
 	{
 		case RTE_RELATION:
 			/* It's a table or view, report it */
 			tle->resorigtbl = rte->relid;
-			tle->resorigcol = attnum;
+			tle->resorigcol = attphysnum;
 			break;
 		case RTE_SUBQUERY:
 			/* Subselect-in-FROM: copy up from the subselect */
-			if (attnum != InvalidAttrNumber)
+			if (attphysnum != InvalidAttrNumber)
 			{
 				TargetEntry *ste = get_tle_by_resno(rte->subquery->targetList,
-													attnum);
+													attphysnum);
 
 				if (ste == NULL || ste->resjunk)
 					elog(ERROR, "subquery %s does not have attribute %d",
-						 rte->eref->aliasname, attnum);
+						 rte->eref->aliasname, attphysnum);
 				tle->resorigtbl = ste->resorigtbl;
 				tle->resorigcol = ste->resorigcol;
 			}
@@ -394,7 +394,7 @@ markTargetListOrigin(ParseState *pstate, TargetEntry *tle,
 			 * recursive CTE, and so any markings on the current targetlist
 			 * are not going to affect the results anyway.
 			 */
-			if (attnum != InvalidAttrNumber && !rte->self_reference)
+			if (attphysnum != InvalidAttrNumber && !rte->self_reference)
 			{
 				CommonTableExpr *cte = GetCTEForRTE(pstate, rte, netlevelsup);
 				TargetEntry *ste;
@@ -410,14 +410,14 @@ markTargetListOrigin(ParseState *pstate, TargetEntry *tle,
 				if (cte->cycle_clause)
 					extra_cols += 2;
 				if (extra_cols &&
-					attnum > list_length(tl) &&
-					attnum <= list_length(tl) + extra_cols)
+					attphysnum > list_length(tl) &&
+					attphysnum <= list_length(tl) + extra_cols)
 					break;
 
-				ste = get_tle_by_resno(tl, attnum);
+				ste = get_tle_by_resno(tl, attphysnum);
 				if (ste == NULL || ste->resjunk)
 					elog(ERROR, "CTE %s does not have attribute %d",
-						 rte->eref->aliasname, attnum);
+						 rte->eref->aliasname, attphysnum);
 				tle->resorigtbl = ste->resorigtbl;
 				tle->resorigcol = ste->resorigcol;
 			}
@@ -745,7 +745,7 @@ transformAssignmentIndirection(ParseState *pstate,
 			Oid			baseTypeId;
 			int32		baseTypeMod;
 			Oid			typrelid;
-			AttrNumber	attnum;
+			AttrNumber	attphysnum;
 			Oid			fieldTypeId;
 			int32		fieldTypMod;
 			Oid			fieldCollation;
@@ -789,22 +789,22 @@ transformAssignmentIndirection(ParseState *pstate,
 								format_type_be(targetTypeId)),
 						 parser_errposition(pstate, location)));
 
-			attnum = get_attnum(typrelid, strVal(n));
-			if (attnum == InvalidAttrNumber)
+			attphysnum = get_attphysnum(typrelid, strVal(n));
+			if (attphysnum == InvalidAttrNumber)
 				ereport(ERROR,
 						(errcode(ERRCODE_UNDEFINED_COLUMN),
 						 errmsg("cannot assign to field \"%s\" of column \"%s\" because there is no such column in data type %s",
 								strVal(n), targetName,
 								format_type_be(targetTypeId)),
 						 parser_errposition(pstate, location)));
-			if (attnum < 0)
+			if (attphysnum < 0)
 				ereport(ERROR,
 						(errcode(ERRCODE_UNDEFINED_COLUMN),
 						 errmsg("cannot assign to system column \"%s\"",
 								strVal(n)),
 						 parser_errposition(pstate, location)));
 
-			get_atttypetypmodcoll(typrelid, attnum,
+			get_atttypetypmodcoll(typrelid, attphysnum,
 								  &fieldTypeId, &fieldTypMod, &fieldCollation);
 
 			/* recurse to create appropriate RHS for field assign */
@@ -825,7 +825,7 @@ transformAssignmentIndirection(ParseState *pstate,
 			fstore = makeNode(FieldStore);
 			fstore->arg = (Expr *) basenode;
 			fstore->newvals = list_make1(rhs);
-			fstore->fieldnums = list_make1_int(attnum);
+			fstore->fieldnums = list_make1_int(attphysnum);
 			fstore->resulttype = baseTypeId;
 
 			/* If target is a domain, apply constraints */
@@ -1512,7 +1512,7 @@ expandRecordVariable(ParseState *pstate, Var *var, int levelsup)
 	TupleDesc	tupleDesc;
 	int			netlevelsup;
 	RangeTblEntry *rte;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	Node	   *expr;
 
 	/* Check my caller didn't mess up */
@@ -1527,9 +1527,9 @@ expandRecordVariable(ParseState *pstate, Var *var, int levelsup)
 	 */
 	netlevelsup = var->varlevelsup + levelsup;
 	rte = GetRTEByRangeTablePosn(pstate, var->varno, netlevelsup);
-	attnum = var->varattno;
+	attphysnum = var->varattno;
 
-	if (attnum == InvalidAttrNumber)
+	if (attphysnum == InvalidAttrNumber)
 	{
 		/* Whole-row reference to an RTE, so expand the known fields */
 		List	   *names,
@@ -1581,11 +1581,11 @@ expandRecordVariable(ParseState *pstate, Var *var, int levelsup)
 			{
 				/* Subselect-in-FROM: examine sub-select's output expr */
 				TargetEntry *ste = get_tle_by_resno(rte->subquery->targetList,
-													attnum);
+													attphysnum);
 
 				if (ste == NULL || ste->resjunk)
 					elog(ERROR, "subquery %s does not have attribute %d",
-						 rte->eref->aliasname, attnum);
+						 rte->eref->aliasname, attphysnum);
 				expr = (Node *) ste->expr;
 				if (IsA(expr, Var))
 				{
@@ -1608,8 +1608,8 @@ expandRecordVariable(ParseState *pstate, Var *var, int levelsup)
 			break;
 		case RTE_JOIN:
 			/* Join RTE --- recursively inspect the alias variable */
-			Assert(attnum > 0 && attnum <= list_length(rte->joinaliasvars));
-			expr = (Node *) list_nth(rte->joinaliasvars, attnum - 1);
+			Assert(attphysnum > 0 && attphysnum <= list_length(rte->joinaliasvars));
+			expr = (Node *) list_nth(rte->joinaliasvars, attphysnum - 1);
 			Assert(expr != NULL);
 			/* We intentionally don't strip implicit coercions here */
 			if (IsA(expr, Var))
@@ -1636,10 +1636,10 @@ expandRecordVariable(ParseState *pstate, Var *var, int levelsup)
 				CommonTableExpr *cte = GetCTEForRTE(pstate, rte, netlevelsup);
 				TargetEntry *ste;
 
-				ste = get_tle_by_resno(GetCTETargetList(cte), attnum);
+				ste = get_tle_by_resno(GetCTETargetList(cte), attphysnum);
 				if (ste == NULL || ste->resjunk)
 					elog(ERROR, "CTE %s does not have attribute %d",
-						 rte->eref->aliasname, attnum);
+						 rte->eref->aliasname, attphysnum);
 				expr = (Node *) ste->expr;
 				if (IsA(expr, Var))
 				{
diff --git a/src/backend/parser/parse_type.c b/src/backend/parser/parse_type.c
index 307114a30d..1959ef3bc1 100644
--- a/src/backend/parser/parse_type.c
+++ b/src/backend/parser/parse_type.c
@@ -89,7 +89,7 @@ LookupTypeNameExtended(ParseState *pstate,
 		RangeVar   *rel = makeRangeVar(NULL, NULL, typeName->location);
 		char	   *field = NULL;
 		Oid			relid;
-		AttrNumber	attnum;
+		AttrNumber	attphysnum;
 
 		/* deconstruct the name list */
 		switch (list_length(typeName->names))
@@ -133,8 +133,8 @@ LookupTypeNameExtended(ParseState *pstate,
 		 * penalty and would also require a permissions check.
 		 */
 		relid = RangeVarGetRelid(rel, NoLock, missing_ok);
-		attnum = get_attnum(relid, field);
-		if (attnum == InvalidAttrNumber)
+		attphysnum = get_attphysnum(relid, field);
+		if (attphysnum == InvalidAttrNumber)
 		{
 			if (missing_ok)
 				typoid = InvalidOid;
@@ -147,7 +147,7 @@ LookupTypeNameExtended(ParseState *pstate,
 		}
 		else
 		{
-			typoid = get_atttype(relid, attnum);
+			typoid = get_atttype(relid, attphysnum);
 
 			/* this construct should never have an array indicator */
 			Assert(typeName->arrayBounds == NIL);
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index 1a64a52279..69132f729d 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -487,7 +487,7 @@ generateSerialExtraStmts(CreateStmtContext *cxt, ColumnDef *column,
 	 * owned by this column, and add it to the appropriate list of things to
 	 * be done along with this CREATE/ALTER TABLE.  In a CREATE or ALTER ADD
 	 * COLUMN, it must be done after the statement because we don't know the
-	 * column's attnum yet.  But if we do have the attnum (in AT_AddIdentity),
+	 * column's attphysnum yet.  But if we do have the attphysnum (in AT_AddIdentity),
 	 * we can do the marking immediately, which improves some ALTER TABLE
 	 * behaviors.
 	 */
@@ -1070,7 +1070,7 @@ transformTableLikeClause(CreateStmtContext *cxt, TableLikeClause *table_like_cla
 			 * find sequence owned by old column; extract sequence parameters;
 			 * build new create sequence command
 			 */
-			seq_relid = getIdentitySequence(RelationGetRelid(relation), attribute->attnum, false);
+			seq_relid = getIdentitySequence(RelationGetRelid(relation), attribute->attphysnum, false);
 			seq_options = sequence_options(seq_relid);
 			generateSerialExtraStmts(cxt, def,
 									 InvalidOid, seq_options,
@@ -1097,7 +1097,7 @@ transformTableLikeClause(CreateStmtContext *cxt, TableLikeClause *table_like_cla
 		if ((table_like_clause->options & CREATE_TABLE_LIKE_COMMENTS) &&
 			(comment = GetComment(attribute->attrelid,
 								  RelationRelationId,
-								  attribute->attnum)) != NULL)
+								  attribute->attphysnum)) != NULL)
 		{
 			CommentStmt *stmt = makeNode(CommentStmt);
 
@@ -1701,20 +1701,20 @@ generateClonedIndexStmt(RangeVar *heapRel, Relation source_idx,
 	for (keyno = 0; keyno < idxrec->indnkeyatts; keyno++)
 	{
 		IndexElem  *iparam;
-		AttrNumber	attnum = idxrec->indkey.values[keyno];
+		AttrNumber	attphysnum = idxrec->indkey.values[keyno];
 		Form_pg_attribute attr = TupleDescAttr(RelationGetDescr(source_idx),
 											   keyno);
 		int16		opt = source_idx->rd_indoption[keyno];
 
 		iparam = makeNode(IndexElem);
 
-		if (AttributeNumberIsValid(attnum))
+		if (AttributeNumberIsValid(attphysnum))
 		{
 			/* Simple index column */
 			char	   *attname;
 
-			attname = get_attname(indrelid, attnum, false);
-			keycoltype = get_atttype(indrelid, attnum);
+			attname = get_attname(indrelid, attphysnum, false);
+			keycoltype = get_atttype(indrelid, attphysnum);
 
 			iparam->name = attname;
 			iparam->expr = NULL;
@@ -1793,18 +1793,18 @@ generateClonedIndexStmt(RangeVar *heapRel, Relation source_idx,
 	for (keyno = idxrec->indnkeyatts; keyno < idxrec->indnatts; keyno++)
 	{
 		IndexElem  *iparam;
-		AttrNumber	attnum = idxrec->indkey.values[keyno];
+		AttrNumber	attphysnum = idxrec->indkey.values[keyno];
 		Form_pg_attribute attr = TupleDescAttr(RelationGetDescr(source_idx),
 											   keyno);
 
 		iparam = makeNode(IndexElem);
 
-		if (AttributeNumberIsValid(attnum))
+		if (AttributeNumberIsValid(attphysnum))
 		{
 			/* Simple index column */
 			char	   *attname;
 
-			attname = get_attname(indrelid, attnum, false);
+			attname = get_attname(indrelid, attphysnum, false);
 
 			iparam->name = attname;
 			iparam->expr = NULL;
@@ -1922,9 +1922,9 @@ generateClonedExtStatsStmt(RangeVar *heapRel, Oid heapRelid,
 	for (i = 0; i < statsrec->stxkeys.dim1; i++)
 	{
 		StatsElem  *selem = makeNode(StatsElem);
-		AttrNumber	attnum = statsrec->stxkeys.values[i];
+		AttrNumber	attphysnum = statsrec->stxkeys.values[i];
 
-		selem->name = get_attname(heapRelid, attnum, false);
+		selem->name = get_attname(heapRelid, attphysnum, false);
 		selem->expr = NULL;
 
 		def_names = lappend(def_names, selem);
@@ -2330,23 +2330,23 @@ transformIndexConstraint(Constraint *constraint, CreateStmtContext *cxt)
 
 		for (i = 0; i < index_form->indnatts; i++)
 		{
-			int16		attnum = index_form->indkey.values[i];
+			int16		attphysnum = index_form->indkey.values[i];
 			const FormData_pg_attribute *attform;
 			char	   *attname;
 			Oid			defopclass;
 
 			/*
-			 * We shouldn't see attnum == 0 here, since we already rejected
+			 * We shouldn't see attphysnum == 0 here, since we already rejected
 			 * expression indexes.  If we do, SystemAttributeDefinition will
 			 * throw an error.
 			 */
-			if (attnum > 0)
+			if (attphysnum > 0)
 			{
-				Assert(attnum <= heap_rel->rd_att->natts);
-				attform = TupleDescAttr(heap_rel->rd_att, attnum - 1);
+				Assert(attphysnum <= heap_rel->rd_att->natts);
+				attform = TupleDescAttr(heap_rel->rd_att, attphysnum - 1);
 			}
 			else
-				attform = SystemAttributeDefinition(attnum);
+				attform = SystemAttributeDefinition(attphysnum);
 			attname = pstrdup(NameStr(attform->attname));
 
 			if (i < index_form->indnkeyatts)
@@ -3400,7 +3400,7 @@ transformAlterTableStmt(Oid relid, AlterTableStmt *stmt,
 			case AT_AlterColumnType:
 				{
 					ColumnDef  *def = castNode(ColumnDef, cmd->def);
-					AttrNumber	attnum;
+					AttrNumber	attphysnum;
 
 					/*
 					 * For ALTER COLUMN TYPE, transform the USING clause if
@@ -3417,17 +3417,17 @@ transformAlterTableStmt(Oid relid, AlterTableStmt *stmt,
 					 * For identity column, create ALTER SEQUENCE command to
 					 * change the data type of the sequence.
 					 */
-					attnum = get_attnum(relid, cmd->name);
-					if (attnum == InvalidAttrNumber)
+					attphysnum = get_attphysnum(relid, cmd->name);
+					if (attphysnum == InvalidAttrNumber)
 						ereport(ERROR,
 								(errcode(ERRCODE_UNDEFINED_COLUMN),
 								 errmsg("column \"%s\" of relation \"%s\" does not exist",
 										cmd->name, RelationGetRelationName(rel))));
 
-					if (attnum > 0 &&
-						TupleDescAttr(tupdesc, attnum - 1)->attidentity)
+					if (attphysnum > 0 &&
+						TupleDescAttr(tupdesc, attphysnum - 1)->attidentity)
 					{
-						Oid			seq_relid = getIdentitySequence(relid, attnum, false);
+						Oid			seq_relid = getIdentitySequence(relid, attphysnum, false);
 						Oid			typeOid = typenameTypeId(pstate, def->typeName);
 						AlterSeqStmt *altseqstmt = makeNode(AlterSeqStmt);
 
@@ -3447,21 +3447,21 @@ transformAlterTableStmt(Oid relid, AlterTableStmt *stmt,
 				{
 					Constraint *def = castNode(Constraint, cmd->def);
 					ColumnDef  *newdef = makeNode(ColumnDef);
-					AttrNumber	attnum;
+					AttrNumber	attphysnum;
 
 					newdef->colname = cmd->name;
 					newdef->identity = def->generated_when;
 					cmd->def = (Node *) newdef;
 
-					attnum = get_attnum(relid, cmd->name);
-					if (attnum == InvalidAttrNumber)
+					attphysnum = get_attphysnum(relid, cmd->name);
+					if (attphysnum == InvalidAttrNumber)
 						ereport(ERROR,
 								(errcode(ERRCODE_UNDEFINED_COLUMN),
 								 errmsg("column \"%s\" of relation \"%s\" does not exist",
 										cmd->name, RelationGetRelationName(rel))));
 
 					generateSerialExtraStmts(&cxt, newdef,
-											 get_atttype(relid, attnum),
+											 get_atttype(relid, attphysnum),
 											 def->options, true, true,
 											 NULL, NULL);
 
@@ -3478,7 +3478,7 @@ transformAlterTableStmt(Oid relid, AlterTableStmt *stmt,
 					ListCell   *lc;
 					List	   *newseqopts = NIL;
 					List	   *newdef = NIL;
-					AttrNumber	attnum;
+					AttrNumber	attphysnum;
 					Oid			seq_relid;
 
 					/*
@@ -3495,14 +3495,14 @@ transformAlterTableStmt(Oid relid, AlterTableStmt *stmt,
 							newseqopts = lappend(newseqopts, def);
 					}
 
-					attnum = get_attnum(relid, cmd->name);
-					if (attnum == InvalidAttrNumber)
+					attphysnum = get_attphysnum(relid, cmd->name);
+					if (attphysnum == InvalidAttrNumber)
 						ereport(ERROR,
 								(errcode(ERRCODE_UNDEFINED_COLUMN),
 								 errmsg("column \"%s\" of relation \"%s\" does not exist",
 										cmd->name, RelationGetRelationName(rel))));
 
-					seq_relid = getIdentitySequence(relid, attnum, true);
+					seq_relid = getIdentitySequence(relid, attphysnum, true);
 
 					if (seq_relid)
 					{
diff --git a/src/backend/replication/basebackup_copy.c b/src/backend/replication/basebackup_copy.c
index cabb077240..38d792884e 100644
--- a/src/backend/replication/basebackup_copy.c
+++ b/src/backend/replication/basebackup_copy.c
@@ -346,7 +346,7 @@ SendXlogRecPtrResult(XLogRecPtr ptr, TimeLineID tli)
 	/* Field headers */
 	pq_sendstring(&buf, "recptr");
 	pq_sendint32(&buf, 0);		/* table oid */
-	pq_sendint16(&buf, 0);		/* attnum */
+	pq_sendint16(&buf, 0);		/* attphysnum */
 	pq_sendint32(&buf, TEXTOID);	/* type oid */
 	pq_sendint16(&buf, -1);
 	pq_sendint32(&buf, 0);
@@ -354,7 +354,7 @@ SendXlogRecPtrResult(XLogRecPtr ptr, TimeLineID tli)
 
 	pq_sendstring(&buf, "tli");
 	pq_sendint32(&buf, 0);		/* table oid */
-	pq_sendint16(&buf, 0);		/* attnum */
+	pq_sendint16(&buf, 0);		/* attphysnum */
 
 	/*
 	 * int8 may seem like a surprising data type for this, but in theory int4
@@ -401,7 +401,7 @@ SendTablespaceList(List *tablespaces)
 	/* First field - spcoid */
 	pq_sendstring(&buf, "spcoid");
 	pq_sendint32(&buf, 0);		/* table oid */
-	pq_sendint16(&buf, 0);		/* attnum */
+	pq_sendint16(&buf, 0);		/* attphysnum */
 	pq_sendint32(&buf, OIDOID); /* type oid */
 	pq_sendint16(&buf, 4);		/* typlen */
 	pq_sendint32(&buf, 0);		/* typmod */
diff --git a/src/backend/replication/logical/proto.c b/src/backend/replication/logical/proto.c
index ff8513e2d2..0e68aa0d9d 100644
--- a/src/backend/replication/logical/proto.c
+++ b/src/backend/replication/logical/proto.c
@@ -47,9 +47,9 @@ static const char *logicalrep_read_namespace(StringInfo in);
  * all columns.
  */
 static bool
-column_in_column_list(int attnum, Bitmapset *columns)
+column_in_column_list(int attphysnum, Bitmapset *columns)
 {
-	return (columns == NULL || bms_is_member(attnum, columns));
+	return (columns == NULL || bms_is_member(attphysnum, columns));
 }
 
 
@@ -783,7 +783,7 @@ logicalrep_write_tuple(StringInfo out, Relation rel, TupleTableSlot *slot,
 		if (att->attisdropped || att->attgenerated)
 			continue;
 
-		if (!column_in_column_list(att->attnum, columns))
+		if (!column_in_column_list(att->attphysnum, columns))
 			continue;
 
 		nliveatts++;
@@ -804,7 +804,7 @@ logicalrep_write_tuple(StringInfo out, Relation rel, TupleTableSlot *slot,
 		if (att->attisdropped || att->attgenerated)
 			continue;
 
-		if (!column_in_column_list(att->attnum, columns))
+		if (!column_in_column_list(att->attphysnum, columns))
 			continue;
 
 		if (isnull[i])
@@ -946,7 +946,7 @@ logicalrep_write_attrs(StringInfo out, Relation rel, Bitmapset *columns)
 		if (att->attisdropped || att->attgenerated)
 			continue;
 
-		if (!column_in_column_list(att->attnum, columns))
+		if (!column_in_column_list(att->attphysnum, columns))
 			continue;
 
 		nliveatts++;
@@ -967,12 +967,12 @@ logicalrep_write_attrs(StringInfo out, Relation rel, Bitmapset *columns)
 		if (att->attisdropped || att->attgenerated)
 			continue;
 
-		if (!column_in_column_list(att->attnum, columns))
+		if (!column_in_column_list(att->attphysnum, columns))
 			continue;
 
 		/* REPLICA IDENTITY FULL means all columns are sent as part of key. */
 		if (replidentfull ||
-			bms_is_member(att->attnum - FirstLowInvalidHeapAttributeNumber,
+			bms_is_member(att->attphysnum - FirstLowInvalidHeapAttributeNumber,
 						  idattrs))
 			flags |= LOGICALREP_IS_REPLICA_IDENTITY;
 
diff --git a/src/backend/replication/logical/relation.c b/src/backend/replication/logical/relation.c
index e989047681..a067446379 100644
--- a/src/backend/replication/logical/relation.c
+++ b/src/backend/replication/logical/relation.c
@@ -290,19 +290,19 @@ logicalrep_rel_mark_updatable(LogicalRepRelMapEntry *entry)
 	i = -1;
 	while ((i = bms_next_member(idkey, i)) >= 0)
 	{
-		int			attnum = i + FirstLowInvalidHeapAttributeNumber;
+		int			attphysnum = i + FirstLowInvalidHeapAttributeNumber;
 
-		if (!AttrNumberIsForUserDefinedAttr(attnum))
+		if (!AttrNumberIsForUserDefinedAttr(attphysnum))
 			ereport(ERROR,
 					(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 					 errmsg("logical replication target relation \"%s.%s\" uses "
 							"system columns in REPLICA IDENTITY index",
 							remoterel->nspname, remoterel->relname)));
 
-		attnum = AttrNumberGetAttrOffset(attnum);
+		attphysnum = AttrNumberGetAttrOffset(attphysnum);
 
-		if (entry->attrmap->attnums[attnum] < 0 ||
-			!bms_is_member(entry->attrmap->attnums[attnum], remoterel->attkeys))
+		if (entry->attrmap->attnums[attphysnum] < 0 ||
+			!bms_is_member(entry->attrmap->attnums[attphysnum], remoterel->attkeys))
 		{
 			entry->updatable = false;
 			break;
@@ -410,7 +410,7 @@ logicalrep_rel_open(LogicalRepRelId remoteid, LOCKMODE lockmode)
 		missingatts = bms_add_range(NULL, 0, remoterel->natts - 1);
 		for (i = 0; i < desc->natts; i++)
 		{
-			int			attnum;
+			int			attphysnum;
 			Form_pg_attribute attr = TupleDescAttr(desc, i);
 
 			if (attr->attisdropped || attr->attgenerated)
@@ -419,12 +419,12 @@ logicalrep_rel_open(LogicalRepRelId remoteid, LOCKMODE lockmode)
 				continue;
 			}
 
-			attnum = logicalrep_rel_att_by_name(remoterel,
+			attphysnum = logicalrep_rel_att_by_name(remoterel,
 												NameStr(attr->attname));
 
-			entry->attrmap->attnums[i] = attnum;
-			if (attnum >= 0)
-				missingatts = bms_del_member(missingatts, attnum);
+			entry->attrmap->attnums[i] = attphysnum;
+			if (attphysnum >= 0)
+				missingatts = bms_del_member(missingatts, attphysnum);
 		}
 
 		logicalrep_report_missing_attrs(remoterel, missingatts);
diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
index 8da5f9089c..2dc47f8e02 100644
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -4668,7 +4668,7 @@ ReorderBufferToastReplace(ReorderBuffer *rb, ReorderBufferTXN *txn,
 		Size		data_done = 0;
 
 		/* system columns aren't toasted */
-		if (attr->attnum < 0)
+		if (attr->attphysnum < 0)
 			continue;
 
 		if (attr->attisdropped)
diff --git a/src/backend/replication/logical/tablesync.c b/src/backend/replication/logical/tablesync.c
index 670c6fcada..ed527173fa 100644
--- a/src/backend/replication/logical/tablesync.c
+++ b/src/backend/replication/logical/tablesync.c
@@ -852,17 +852,17 @@ fetch_remote_table_info(char *nspname, char *relname,
 	 */
 	resetStringInfo(&cmd);
 	appendStringInfo(&cmd,
-					 "SELECT a.attnum,"
+					 "SELECT a.attphysnum,"
 					 "       a.attname,"
 					 "       a.atttypid,"
-					 "       a.attnum = ANY(i.indkey)"
+					 "       a.attphysnum = ANY(i.indkey)"
 					 "  FROM pg_catalog.pg_attribute a"
 					 "  LEFT JOIN pg_catalog.pg_index i"
 					 "       ON (i.indexrelid = pg_get_replica_identity_index(%u))"
-					 " WHERE a.attnum > 0::pg_catalog.int2"
+					 " WHERE a.attphysnum > 0::pg_catalog.int2"
 					 "   AND NOT a.attisdropped %s"
 					 "   AND a.attrelid = %u"
-					 " ORDER BY a.attnum",
+					 " ORDER BY a.attphysnum",
 					 lrel->remoteid,
 					 (walrcv_server_version(LogRepWorkerWalRcvConn) >= 120000 ?
 					  "AND a.attgenerated = ''" : ""),
@@ -890,13 +890,13 @@ fetch_remote_table_info(char *nspname, char *relname,
 	while (tuplestore_gettupleslot(res->tuplestore, true, false, slot))
 	{
 		char	   *rel_colname;
-		AttrNumber	attnum;
+		AttrNumber	attphysnum;
 
-		attnum = DatumGetInt16(slot_getattr(slot, 1, &isnull));
+		attphysnum = DatumGetInt16(slot_getattr(slot, 1, &isnull));
 		Assert(!isnull);
 
 		/* If the column is not in the column list, skip it. */
-		if (included_cols != NULL && !bms_is_member(attnum, included_cols))
+		if (included_cols != NULL && !bms_is_member(attphysnum, included_cols))
 		{
 			ExecClearTuple(slot);
 			continue;
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index 38e3b1c1b3..89da19e43f 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -562,7 +562,7 @@ slot_fill_defaults(LogicalRepRelMapEntry *rel, EState *estate,
 	TupleDesc	desc = RelationGetDescr(rel->localrel);
 	int			num_phys_attrs = desc->natts;
 	int			i;
-	int			attnum,
+	int			attphysnum,
 				num_defaults = 0;
 	int		   *defmap;
 	ExprState **defexprs;
@@ -578,17 +578,17 @@ slot_fill_defaults(LogicalRepRelMapEntry *rel, EState *estate,
 	defexprs = (ExprState **) palloc(num_phys_attrs * sizeof(ExprState *));
 
 	Assert(rel->attrmap->maplen == num_phys_attrs);
-	for (attnum = 0; attnum < num_phys_attrs; attnum++)
+	for (attphysnum = 0; attphysnum < num_phys_attrs; attphysnum++)
 	{
 		Expr	   *defexpr;
 
-		if (TupleDescAttr(desc, attnum)->attisdropped || TupleDescAttr(desc, attnum)->attgenerated)
+		if (TupleDescAttr(desc, attphysnum)->attisdropped || TupleDescAttr(desc, attphysnum)->attgenerated)
 			continue;
 
-		if (rel->attrmap->attnums[attnum] >= 0)
+		if (rel->attrmap->attnums[attphysnum] >= 0)
 			continue;
 
-		defexpr = (Expr *) build_column_default(rel->localrel, attnum + 1);
+		defexpr = (Expr *) build_column_default(rel->localrel, attphysnum + 1);
 
 		if (defexpr != NULL)
 		{
@@ -597,7 +597,7 @@ slot_fill_defaults(LogicalRepRelMapEntry *rel, EState *estate,
 
 			/* Initialize executable expression in copycontext */
 			defexprs[num_defaults] = ExecInitExpr(defexpr, NULL);
-			defmap[num_defaults] = attnum;
+			defmap[num_defaults] = attphysnum;
 			num_defaults++;
 		}
 	}
@@ -634,7 +634,7 @@ slot_store_data(TupleTableSlot *slot, LogicalRepRelMapEntry *rel,
 
 			Assert(remoteattnum < tupleData->ncols);
 
-			/* Set attnum for error callback */
+			/* Set attphysnum for error callback */
 			apply_error_callback_arg.remote_attnum = remoteattnum;
 
 			if (tupleData->colstatus[remoteattnum] == LOGICALREP_COLUMN_TEXT)
@@ -683,7 +683,7 @@ slot_store_data(TupleTableSlot *slot, LogicalRepRelMapEntry *rel,
 				slot->tts_isnull[i] = true;
 			}
 
-			/* Reset attnum for error callback */
+			/* Reset attphysnum for error callback */
 			apply_error_callback_arg.remote_attnum = -1;
 		}
 		else
@@ -749,7 +749,7 @@ slot_modify_data(TupleTableSlot *slot, TupleTableSlot *srcslot,
 		{
 			StringInfo	colvalue = &tupleData->colvalues[remoteattnum];
 
-			/* Set attnum for error callback */
+			/* Set attphysnum for error callback */
 			apply_error_callback_arg.remote_attnum = remoteattnum;
 
 			if (tupleData->colstatus[remoteattnum] == LOGICALREP_COLUMN_TEXT)
@@ -794,7 +794,7 @@ slot_modify_data(TupleTableSlot *slot, TupleTableSlot *srcslot,
 				slot->tts_isnull[i] = true;
 			}
 
-			/* Reset attnum for error callback */
+			/* Reset attphysnum for error callback */
 			apply_error_callback_arg.remote_attnum = -1;
 		}
 	}
diff --git a/src/backend/replication/pgoutput/pgoutput.c b/src/backend/replication/pgoutput/pgoutput.c
index 8deae57143..caa4b4e9e2 100644
--- a/src/backend/replication/pgoutput/pgoutput.c
+++ b/src/backend/replication/pgoutput/pgoutput.c
@@ -737,7 +737,7 @@ send_relation_and_attrs(Relation relation, TransactionId xid,
 			continue;
 
 		/* Skip this attribute if it's not present in the column list */
-		if (columns != NULL && !bms_is_member(att->attnum, columns))
+		if (columns != NULL && !bms_is_member(att->attphysnum, columns))
 			continue;
 
 		OutputPluginPrepareWrite(ctx, false);
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index e42671722a..6b6430f941 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -602,7 +602,7 @@ SendTimeLineHistory(TimeLineHistoryCmd *cmd)
 	/* first field */
 	pq_sendstring(&buf, "filename");	/* col name */
 	pq_sendint32(&buf, 0);		/* table oid */
-	pq_sendint16(&buf, 0);		/* attnum */
+	pq_sendint16(&buf, 0);		/* attphysnum */
 	pq_sendint32(&buf, TEXTOID);	/* type oid */
 	pq_sendint16(&buf, -1);		/* typlen */
 	pq_sendint32(&buf, 0);		/* typmod */
@@ -611,7 +611,7 @@ SendTimeLineHistory(TimeLineHistoryCmd *cmd)
 	/* second field */
 	pq_sendstring(&buf, "content"); /* col name */
 	pq_sendint32(&buf, 0);		/* table oid */
-	pq_sendint16(&buf, 0);		/* attnum */
+	pq_sendint16(&buf, 0);		/* attphysnum */
 	pq_sendint32(&buf, TEXTOID);	/* type oid */
 	pq_sendint16(&buf, -1);		/* typlen */
 	pq_sendint32(&buf, 0);		/* typmod */
diff --git a/src/backend/statistics/dependencies.c b/src/backend/statistics/dependencies.c
index c1c27e67d4..db14e35c86 100644
--- a/src/backend/statistics/dependencies.c
+++ b/src/backend/statistics/dependencies.c
@@ -76,7 +76,7 @@ static double dependency_degree(StatsBuildData *data, int k, AttrNumber *depende
 static bool dependency_is_fully_matched(MVDependency *dependency,
 										Bitmapset *attnums);
 static bool dependency_is_compatible_clause(Node *clause, Index relid,
-											AttrNumber *attnum);
+											AttrNumber *attphysnum);
 static bool dependency_is_compatible_expression(Node *clause, Index relid,
 												List *statlist, Node **expr);
 static MVDependency *find_strongest_dependency(MVDependencies **dependencies,
@@ -604,9 +604,9 @@ dependency_is_fully_matched(MVDependency *dependency, Bitmapset *attnums)
 	 */
 	for (j = 0; j < dependency->nattributes; j++)
 	{
-		int			attnum = dependency->attributes[j];
+		int			attphysnum = dependency->attributes[j];
 
-		if (!bms_is_member(attnum, attnums))
+		if (!bms_is_member(attphysnum, attnums))
 			return false;
 	}
 
@@ -737,10 +737,10 @@ pg_dependencies_send(PG_FUNCTION_ARGS)
  * Only clauses that have the form of equality to a pseudoconstant, or can be
  * interpreted that way, are currently accepted.  Furthermore the variable
  * part of the clause must be a simple Var belonging to the specified
- * relation, whose attribute number we return in *attnum on success.
+ * relation, whose attribute number we return in *attphysnum on success.
  */
 static bool
-dependency_is_compatible_clause(Node *clause, Index relid, AttrNumber *attnum)
+dependency_is_compatible_clause(Node *clause, Index relid, AttrNumber *attphysnum)
 {
 	Var		   *var;
 	Node	   *clause_expr;
@@ -839,7 +839,7 @@ dependency_is_compatible_clause(Node *clause, Index relid, AttrNumber *attnum)
 		ListCell   *lc;
 
 		/* start with no attribute number */
-		*attnum = InvalidAttrNumber;
+		*attphysnum = InvalidAttrNumber;
 
 		foreach(lc, bool_expr->args)
 		{
@@ -853,11 +853,11 @@ dependency_is_compatible_clause(Node *clause, Index relid, AttrNumber *attnum)
 												 relid, &clause_attnum))
 				return false;
 
-			if (*attnum == InvalidAttrNumber)
-				*attnum = clause_attnum;
+			if (*attphysnum == InvalidAttrNumber)
+				*attphysnum = clause_attnum;
 
-			/* ensure all the variables are the same (same attnum) */
-			if (*attnum != clause_attnum)
+			/* ensure all the variables are the same (same attphysnum) */
+			if (*attphysnum != clause_attnum)
 				return false;
 		}
 
@@ -907,7 +907,7 @@ dependency_is_compatible_clause(Node *clause, Index relid, AttrNumber *attnum)
 	if (!AttrNumberIsForUserDefinedAttr(var->varattno))
 		return false;
 
-	*attnum = var->varattno;
+	*attphysnum = var->varattno;
 	return true;
 }
 
@@ -1041,9 +1041,9 @@ clauselist_apply_dependencies(PlannerInfo *root, List *clauses,
 	{
 		for (j = 0; j < dependencies[i]->nattributes; j++)
 		{
-			AttrNumber	attnum = dependencies[i]->attributes[j];
+			AttrNumber	attphysnum = dependencies[i]->attributes[j];
 
-			attnums = bms_add_member(attnums, attnum);
+			attnums = bms_add_member(attnums, attphysnum);
 		}
 	}
 
@@ -1106,7 +1106,7 @@ clauselist_apply_dependencies(PlannerInfo *root, List *clauses,
 	for (i = ndependencies - 1; i >= 0; i--)
 	{
 		MVDependency *dependency = dependencies[i];
-		AttrNumber	attnum;
+		AttrNumber	attphysnum;
 		Selectivity s2;
 		double		f;
 
@@ -1114,14 +1114,14 @@ clauselist_apply_dependencies(PlannerInfo *root, List *clauses,
 		s1 = 1.0;
 		for (j = 0; j < dependency->nattributes - 1; j++)
 		{
-			attnum = dependency->attributes[j];
-			attidx = bms_member_index(attnums, attnum);
+			attphysnum = dependency->attributes[j];
+			attidx = bms_member_index(attnums, attphysnum);
 			s1 *= attr_sel[attidx];
 		}
 
 		/* Original selectivity of the implied attribute */
-		attnum = dependency->attributes[j];
-		attidx = bms_member_index(attnums, attnum);
+		attphysnum = dependency->attributes[j];
+		attidx = bms_member_index(attnums, attphysnum);
 		s2 = attr_sel[attidx];
 
 		/*
@@ -1454,7 +1454,7 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 	foreach(l, clauses)
 	{
 		Node	   *clause = (Node *) lfirst(l);
-		AttrNumber	attnum;
+		AttrNumber	attphysnum;
 		Node	   *expr = NULL;
 
 		/* ignore clause by default */
@@ -1464,19 +1464,19 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 		{
 			/*
 			 * If it's a simple column reference, just extract the attnum. If
-			 * it's an expression, assign a negative attnum as if it was a
+			 * it's an expression, assign a negative attphysnum as if it was a
 			 * system attribute.
 			 */
-			if (dependency_is_compatible_clause(clause, rel->relid, &attnum))
+			if (dependency_is_compatible_clause(clause, rel->relid, &attphysnum))
 			{
-				list_attnums[listidx] = attnum;
+				list_attnums[listidx] = attphysnum;
 			}
 			else if (dependency_is_compatible_expression(clause, rel->relid,
 														 rel->statlist,
 														 &expr))
 			{
-				/* special attnum assigned to this expression */
-				attnum = InvalidAttrNumber;
+				/* special attphysnum assigned to this expression */
+				attphysnum = InvalidAttrNumber;
 
 				Assert(expr != NULL);
 
@@ -1486,22 +1486,22 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 					if (equal(unique_exprs[i], expr))
 					{
 						/* negative attribute number to expression */
-						attnum = -(i + 1);
+						attphysnum = -(i + 1);
 						break;
 					}
 				}
 
 				/* not found in the list, so add it */
-				if (attnum == InvalidAttrNumber)
+				if (attphysnum == InvalidAttrNumber)
 				{
 					unique_exprs[unique_exprs_cnt++] = expr;
 
 					/* after incrementing the value, to get -1, -2, ... */
-					attnum = (-unique_exprs_cnt);
+					attphysnum = (-unique_exprs_cnt);
 				}
 
-				/* remember which attnum was assigned to this clause */
-				list_attnums[listidx] = attnum;
+				/* remember which attphysnum was assigned to this clause */
+				list_attnums[listidx] = attphysnum;
 			}
 		}
 
@@ -1526,39 +1526,39 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 	 */
 	for (i = 0; i < list_length(clauses); i++)
 	{
-		AttrNumber	attnum;
+		AttrNumber	attphysnum;
 
 		/* ignore incompatible or already estimated clauses */
 		if (list_attnums[i] == InvalidAttrNumber)
 			continue;
 
-		/* make sure the attnum is in the expected range */
+		/* make sure the attphysnum is in the expected range */
 		Assert(list_attnums[i] >= (-unique_exprs_cnt));
 		Assert(list_attnums[i] <= MaxHeapAttributeNumber);
 
-		/* make sure the attnum is positive (valid AttrNumber) */
-		attnum = list_attnums[i] + attnum_offset;
+		/* make sure the attphysnum is positive (valid AttrNumber) */
+		attphysnum = list_attnums[i] + attnum_offset;
 
 		/*
 		 * Either it's a regular attribute, or it's an expression, in which
 		 * case we must not have seen it before (expressions are unique).
 		 *
 		 * XXX Check whether it's a regular attribute has to be done using the
-		 * original attnum, while the second check has to use the value with
+		 * original attphysnum, while the second check has to use the value with
 		 * an offset.
 		 */
 		Assert(AttrNumberIsForUserDefinedAttr(list_attnums[i]) ||
-			   !bms_is_member(attnum, clauses_attnums));
+			   !bms_is_member(attphysnum, clauses_attnums));
 
 		/*
-		 * Remember the offset attnum, both for attributes and expressions.
+		 * Remember the offset attphysnum, both for attributes and expressions.
 		 * We'll pass list_attnums to clauselist_apply_dependencies, which
 		 * uses it to identify clauses in a bitmap. We could also pass the
 		 * offset, but this is more convenient.
 		 */
-		list_attnums[i] = attnum;
+		list_attnums[i] = attphysnum;
 
-		clauses_attnums = bms_add_member(clauses_attnums, attnum);
+		clauses_attnums = bms_add_member(clauses_attnums, attphysnum);
 	}
 
 	/*
@@ -1606,7 +1606,7 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 			continue;
 
 		/*
-		 * Count matching attributes - we have to undo the attnum offsets. The
+		 * Count matching attributes - we have to undo the attphysnum offsets. The
 		 * input attribute numbers are not offset (expressions are not
 		 * included in stat->keys, so it's not necessary). But we need to
 		 * offset it before checking against clauses_attnums.
@@ -1615,16 +1615,16 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 		k = -1;
 		while ((k = bms_next_member(stat->keys, k)) >= 0)
 		{
-			AttrNumber	attnum = (AttrNumber) k;
+			AttrNumber	attphysnum = (AttrNumber) k;
 
 			/* skip expressions */
-			if (!AttrNumberIsForUserDefinedAttr(attnum))
+			if (!AttrNumberIsForUserDefinedAttr(attphysnum))
 				continue;
 
 			/* apply the same offset as above */
-			attnum += attnum_offset;
+			attphysnum += attnum_offset;
 
-			if (bms_is_member(attnum, clauses_attnums))
+			if (bms_is_member(attphysnum, clauses_attnums))
 				nmatched++;
 		}
 
@@ -1695,20 +1695,20 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 					Node	   *expr;
 					int			k;
 					AttrNumber	unique_attnum = InvalidAttrNumber;
-					AttrNumber	attnum;
+					AttrNumber	attphysnum;
 
 					/* undo the per-statistics offset */
-					attnum = dep->attributes[j];
+					attphysnum = dep->attributes[j];
 
 					/*
 					 * For regular attributes we can simply check if it
 					 * matches any clause. If there's no matching clause, we
-					 * can just ignore it. We need to offset the attnum
+					 * can just ignore it. We need to offset the attphysnum
 					 * though.
 					 */
-					if (AttrNumberIsForUserDefinedAttr(attnum))
+					if (AttrNumberIsForUserDefinedAttr(attphysnum))
 					{
-						dep->attributes[j] = attnum + attnum_offset;
+						dep->attributes[j] = attphysnum + attnum_offset;
 
 						if (!bms_is_member(dep->attributes[j], clauses_attnums))
 						{
@@ -1720,20 +1720,20 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 					}
 
 					/*
-					 * the attnum should be a valid system attnum (-1, -2,
+					 * the attphysnum should be a valid system attphysnum (-1, -2,
 					 * ...)
 					 */
-					Assert(AttributeNumberIsValid(attnum));
+					Assert(AttributeNumberIsValid(attphysnum));
 
 					/*
 					 * For expressions, we need to do two translations. First
-					 * we have to translate the negative attnum to index in
+					 * we have to translate the negative attphysnum to index in
 					 * the list of expressions (in the statistics object).
 					 * Then we need to see if there's a matching clause. The
-					 * index of the unique expression determines the attnum
+					 * index of the unique expression determines the attphysnum
 					 * (and we offset it).
 					 */
-					idx = -(1 + attnum);
+					idx = -(1 + attphysnum);
 
 					/* Is the expression index is valid? */
 					Assert((idx >= 0) && (idx < list_length(stat->exprs)));
@@ -1744,7 +1744,7 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 					for (k = 0; k < unique_exprs_cnt; k++)
 					{
 						/*
-						 * found a matching unique expression, use the attnum
+						 * found a matching unique expression, use the attphysnum
 						 * (derived from index of the unique expression)
 						 */
 						if (equal(unique_exprs[k], expr))
@@ -1765,7 +1765,7 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 						break;
 					}
 
-					/* otherwise remap it to the new attnum */
+					/* otherwise remap it to the new attphysnum */
 					dep->attributes[j] = unique_attnum;
 				}
 
@@ -1816,7 +1816,7 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 	while (true)
 	{
 		MVDependency *dependency;
-		AttrNumber	attnum;
+		AttrNumber	attphysnum;
 
 		/* the widest/strongest dependency, fully matched by clauses */
 		dependency = find_strongest_dependency(func_dependencies,
@@ -1828,8 +1828,8 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 		dependencies[ndependencies++] = dependency;
 
 		/* Ignore dependencies using this implied attribute in later loops */
-		attnum = dependency->attributes[dependency->nattributes - 1];
-		clauses_attnums = bms_del_member(clauses_attnums, attnum);
+		attphysnum = dependency->attributes[dependency->nattributes - 1];
+		clauses_attnums = bms_del_member(clauses_attnums, attphysnum);
 	}
 
 	/*
diff --git a/src/backend/statistics/extended_stats.c b/src/backend/statistics/extended_stats.c
index ca48395d5c..b11db27812 100644
--- a/src/backend/statistics/extended_stats.c
+++ b/src/backend/statistics/extended_stats.c
@@ -391,31 +391,31 @@ statext_compute_stattarget(int stattarget, int nattrs, VacAttrStats **stats)
 bool
 statext_is_kind_built(HeapTuple htup, char type)
 {
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 
 	switch (type)
 	{
 		case STATS_EXT_NDISTINCT:
-			attnum = Anum_pg_statistic_ext_data_stxdndistinct;
+			attphysnum = Anum_pg_statistic_ext_data_stxdndistinct;
 			break;
 
 		case STATS_EXT_DEPENDENCIES:
-			attnum = Anum_pg_statistic_ext_data_stxddependencies;
+			attphysnum = Anum_pg_statistic_ext_data_stxddependencies;
 			break;
 
 		case STATS_EXT_MCV:
-			attnum = Anum_pg_statistic_ext_data_stxdmcv;
+			attphysnum = Anum_pg_statistic_ext_data_stxdmcv;
 			break;
 
 		case STATS_EXT_EXPRESSIONS:
-			attnum = Anum_pg_statistic_ext_data_stxdexpr;
+			attphysnum = Anum_pg_statistic_ext_data_stxdexpr;
 			break;
 
 		default:
 			elog(ERROR, "unexpected statistics type requested: %d", type);
 	}
 
-	return !heap_attisnull(htup, attnum, NULL);
+	return !heap_attisnull(htup, attphysnum, NULL);
 }
 
 /*
@@ -655,7 +655,7 @@ examine_expression(Node *expr, int stattarget)
 
 	/* initialize some basic fields */
 	stats->attr->attrelid = InvalidOid;
-	stats->attr->attnum = InvalidAttrNumber;
+	stats->attr->attphysnum = InvalidAttrNumber;
 	stats->attr->atttypid = stats->attrtypid;
 
 	typtuple = SearchSysCacheCopy1(TYPEOID,
@@ -722,7 +722,7 @@ lookup_var_attr_stats(Relation rel, Bitmapset *attrs, List *exprs,
 
 	stats = (VacAttrStats **) palloc(natts * sizeof(VacAttrStats *));
 
-	/* lookup VacAttrStats info for the requested columns (same attnum) */
+	/* lookup VacAttrStats info for the requested columns (same attphysnum) */
 	while ((x = bms_next_member(attrs, x)) >= 0)
 	{
 		int			j;
@@ -979,7 +979,7 @@ build_attnums_array(Bitmapset *attrs, int nexprs, int *numattrs)
 	j = -1;
 	while ((j = bms_next_member(attrs, j)) >= 0)
 	{
-		int			attnum = (j - nexprs);
+		int			attphysnum = (j - nexprs);
 
 		/*
 		 * Make sure the bitmap contains only user-defined attributes. As
@@ -987,11 +987,11 @@ build_attnums_array(Bitmapset *attrs, int nexprs, int *numattrs)
 		 * ways. Firstly, the bitmap might contain 0 as a member, and secondly
 		 * the integer value might be larger than MaxAttrNumber.
 		 */
-		Assert(AttributeNumberIsValid(attnum));
-		Assert(attnum <= MaxAttrNumber);
-		Assert(attnum >= (-nexprs));
+		Assert(AttributeNumberIsValid(attphysnum));
+		Assert(attphysnum <= MaxAttrNumber);
+		Assert(attphysnum >= (-nexprs));
 
-		attnums[i++] = (AttrNumber) attnum;
+		attnums[i++] = (AttrNumber) attphysnum;
 
 		/* protect against overflows */
 		Assert(i <= num);
@@ -1070,14 +1070,14 @@ build_sorted_items(StatsBuildData *data, int *nitems,
 			Datum		value;
 			bool		isnull;
 			int			attlen;
-			AttrNumber	attnum = attnums[j];
+			AttrNumber	attphysnum = attnums[j];
 
 			int			idx;
 
-			/* match attnum to the pre-calculated data */
+			/* match attphysnum to the pre-calculated data */
 			for (idx = 0; idx < data->nattnums; idx++)
 			{
-				if (attnum == data->attnums[idx])
+				if (attphysnum == data->attnums[idx])
 					break;
 			}
 
@@ -1635,11 +1635,11 @@ statext_is_compatible_clause(PlannerInfo *root, Node *clause, Index relid,
 		else
 		{
 			/* Check the columns referenced by the clause */
-			int			attnum = -1;
+			int			attphysnum = -1;
 
-			while ((attnum = bms_next_member(clause_attnums, attnum)) >= 0)
+			while ((attphysnum = bms_next_member(clause_attnums, attphysnum)) >= 0)
 			{
-				if (pg_attribute_aclcheck(rte->relid, attnum, userid,
+				if (pg_attribute_aclcheck(rte->relid, attphysnum, userid,
 										  ACL_SELECT) != ACLCHECK_OK)
 					return false;
 			}
@@ -2186,7 +2186,7 @@ compute_expr_stats(Relation onerel, double totalrows,
 		{
 			AttributeOpts *aopt =
 			get_attribute_options(stats->attr->attrelid,
-								  stats->attr->attnum);
+								  stats->attr->attphysnum);
 
 			stats->exprvals = exprvals;
 			stats->exprnulls = exprnulls;
diff --git a/src/backend/statistics/mvdistinct.c b/src/backend/statistics/mvdistinct.c
index 6ade5eff78..e8e8682c8a 100644
--- a/src/backend/statistics/mvdistinct.c
+++ b/src/backend/statistics/mvdistinct.c
@@ -373,9 +373,9 @@ pg_ndistinct_out(PG_FUNCTION_ARGS)
 
 		for (j = 0; j < item.nattributes; j++)
 		{
-			AttrNumber	attnum = item.attributes[j];
+			AttrNumber	attphysnum = item.attributes[j];
 
-			appendStringInfo(&str, "%s%d", (j == 0) ? "\"" : ", ", attnum);
+			appendStringInfo(&str, "%s%d", (j == 0) ? "\"" : ", ", attphysnum);
 		}
 		appendStringInfo(&str, "\": %d", (int) item.ndistinct);
 	}
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index 772c04155c..0659109257 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -2444,13 +2444,13 @@ has_any_column_privilege_id_id(PG_FUNCTION_ARGS)
  * has_column_privilege variants
  *		These are all named "has_column_privilege" at the SQL level.
  *		They take various combinations of relation name, relation OID,
- *		column name, column attnum, user name, user OID, or
+ *		column name, column attphysnum, user name, user OID, or
  *		implicit user = current_user.
  *
  *		The result is a boolean value: true if user has the indicated
  *		privilege, false if not.  The variants that take a relation OID
  *		return NULL (rather than throwing an error) if that relation OID
- *		doesn't exist.  Likewise, the variants that take an integer attnum
+ *		doesn't exist.  Likewise, the variants that take an integer attphysnum
  *		return NULL (rather than throwing an error) if there is no such
  *		pg_attribute entry.  All variants return NULL if an attisdropped
  *		column is selected.  These rules are meant to avoid unnecessary
@@ -2464,7 +2464,7 @@ has_any_column_privilege_id_id(PG_FUNCTION_ARGS)
  * Returns 1 if have the privilege, 0 if not, -1 if dropped column/table.
  */
 static int
-column_privilege_check(Oid tableoid, AttrNumber attnum,
+column_privilege_check(Oid tableoid, AttrNumber attphysnum,
 					   Oid roleid, AclMode mode)
 {
 	AclResult	aclresult;
@@ -2473,7 +2473,7 @@ column_privilege_check(Oid tableoid, AttrNumber attnum,
 	/*
 	 * If convert_column_name failed, we can just return -1 immediately.
 	 */
-	if (attnum == InvalidAttrNumber)
+	if (attphysnum == InvalidAttrNumber)
 		return -1;
 
 	/*
@@ -2481,7 +2481,7 @@ column_privilege_check(Oid tableoid, AttrNumber attnum,
 	 * on whether the column even exists, so we need to do it before checking
 	 * table-level privilege.
 	 */
-	aclresult = pg_attribute_aclcheck_ext(tableoid, attnum, roleid,
+	aclresult = pg_attribute_aclcheck_ext(tableoid, attphysnum, roleid,
 										  mode, &is_missing);
 	if (aclresult == ACLCHECK_OK)
 		return 1;
@@ -2530,7 +2530,7 @@ has_column_privilege_name_name_name(PG_FUNCTION_ARGS)
 /*
  * has_column_privilege_name_name_attnum
  *		Check user privileges on a column given
- *		name username, text tablename, int attnum, and text priv name.
+ *		name username, text tablename, int attphysnum, and text priv name.
  */
 Datum
 has_column_privilege_name_name_attnum(PG_FUNCTION_ARGS)
@@ -2584,7 +2584,7 @@ has_column_privilege_name_id_name(PG_FUNCTION_ARGS)
 /*
  * has_column_privilege_name_id_attnum
  *		Check user privileges on a column given
- *		name username, table oid, int attnum, and text priv name.
+ *		name username, table oid, int attphysnum, and text priv name.
  */
 Datum
 has_column_privilege_name_id_attnum(PG_FUNCTION_ARGS)
@@ -2636,7 +2636,7 @@ has_column_privilege_id_name_name(PG_FUNCTION_ARGS)
 /*
  * has_column_privilege_id_name_attnum
  *		Check user privileges on a column given
- *		oid roleid, text tablename, int attnum, and text priv name.
+ *		oid roleid, text tablename, int attphysnum, and text priv name.
  */
 Datum
 has_column_privilege_id_name_attnum(PG_FUNCTION_ARGS)
@@ -2686,7 +2686,7 @@ has_column_privilege_id_id_name(PG_FUNCTION_ARGS)
 /*
  * has_column_privilege_id_id_attnum
  *		Check user privileges on a column given
- *		oid roleid, table oid, int attnum, and text priv name.
+ *		oid roleid, table oid, int attphysnum, and text priv name.
  */
 Datum
 has_column_privilege_id_id_attnum(PG_FUNCTION_ARGS)
@@ -2738,7 +2738,7 @@ has_column_privilege_name_name(PG_FUNCTION_ARGS)
 /*
  * has_column_privilege_name_attnum
  *		Check user privileges on a column given
- *		text tablename, int attnum, and text priv name.
+ *		text tablename, int attphysnum, and text priv name.
  *		current_user is assumed
  */
 Datum
@@ -2792,7 +2792,7 @@ has_column_privilege_id_name(PG_FUNCTION_ARGS)
 /*
  * has_column_privilege_id_attnum
  *		Check user privileges on a column given
- *		table oid, int attnum, and text priv name.
+ *		table oid, int attphysnum, and text priv name.
  *		current_user is assumed
  */
 Datum
@@ -2828,12 +2828,12 @@ convert_column_name(Oid tableoid, text *column)
 {
 	char	   *colname;
 	HeapTuple	attTuple;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 
 	colname = text_to_cstring(column);
 
 	/*
-	 * We don't use get_attnum() here because it will report that dropped
+	 * We don't use get_attphysnum() here because it will report that dropped
 	 * columns don't exist.  We need to treat dropped columns differently from
 	 * nonexistent columns.
 	 */
@@ -2847,9 +2847,9 @@ convert_column_name(Oid tableoid, text *column)
 		attributeForm = (Form_pg_attribute) GETSTRUCT(attTuple);
 		/* We want to return NULL for dropped columns */
 		if (attributeForm->attisdropped)
-			attnum = InvalidAttrNumber;
+			attphysnum = InvalidAttrNumber;
 		else
-			attnum = attributeForm->attnum;
+			attphysnum = attributeForm->attphysnum;
 		ReleaseSysCache(attTuple);
 	}
 	else
@@ -2870,11 +2870,11 @@ convert_column_name(Oid tableoid, text *column)
 							colname, tablename)));
 		}
 		/* tableoid doesn't exist, so act like attisdropped case */
-		attnum = InvalidAttrNumber;
+		attphysnum = InvalidAttrNumber;
 	}
 
 	pfree(colname);
-	return attnum;
+	return attphysnum;
 }
 
 /*
diff --git a/src/backend/utils/adt/expandedrecord.c b/src/backend/utils/adt/expandedrecord.c
index 3b3e0a9106..18951a40ce 100644
--- a/src/backend/utils/adt/expandedrecord.c
+++ b/src/backend/utils/adt/expandedrecord.c
@@ -1031,7 +1031,7 @@ expanded_record_lookup_field(ExpandedRecordHeader *erh, const char *fieldname,
 		if (namestrcmp(&attr->attname, fieldname) == 0 &&
 			!attr->attisdropped)
 		{
-			finfo->fnumber = attr->attnum;
+			finfo->fnumber = attr->attphysnum;
 			finfo->ftypeid = attr->atttypid;
 			finfo->ftypmod = attr->atttypmod;
 			finfo->fcollation = attr->attcollation;
@@ -1043,7 +1043,7 @@ expanded_record_lookup_field(ExpandedRecordHeader *erh, const char *fieldname,
 	sysattr = SystemAttributeByName(fieldname);
 	if (sysattr != NULL)
 	{
-		finfo->fnumber = sysattr->attnum;
+		finfo->fnumber = sysattr->attphysnum;
 		finfo->ftypeid = sysattr->atttypid;
 		finfo->ftypmod = sysattr->atttypmod;
 		finfo->fcollation = sysattr->attcollation;
diff --git a/src/backend/utils/adt/misc.c b/src/backend/utils/adt/misc.c
index 89690be2ed..5ad1cdc905 100644
--- a/src/backend/utils/adt/misc.c
+++ b/src/backend/utils/adt/misc.c
@@ -636,13 +636,13 @@ Datum
 pg_column_is_updatable(PG_FUNCTION_ARGS)
 {
 	Oid			reloid = PG_GETARG_OID(0);
-	AttrNumber	attnum = PG_GETARG_INT16(1);
-	AttrNumber	col = attnum - FirstLowInvalidHeapAttributeNumber;
+	AttrNumber	attphysnum = PG_GETARG_INT16(1);
+	AttrNumber	col = attphysnum - FirstLowInvalidHeapAttributeNumber;
 	bool		include_triggers = PG_GETARG_BOOL(2);
 	int			events;
 
 	/* System columns are never updatable */
-	if (attnum <= 0)
+	if (attphysnum <= 0)
 		PG_RETURN_BOOL(false);
 
 	events = relation_is_updatable(reloid, NIL, include_triggers,
diff --git a/src/backend/utils/adt/ri_triggers.c b/src/backend/utils/adt/ri_triggers.c
index 51b3fdc9a0..cb28faa420 100644
--- a/src/backend/utils/adt/ri_triggers.c
+++ b/src/backend/utils/adt/ri_triggers.c
@@ -85,9 +85,9 @@
 #define MAX_QUOTED_NAME_LEN  (NAMEDATALEN*2+3)
 #define MAX_QUOTED_REL_NAME_LEN  (MAX_QUOTED_NAME_LEN*2)
 
-#define RIAttName(rel, attnum)	NameStr(*attnumAttName(rel, attnum))
-#define RIAttType(rel, attnum)	attnumTypeId(rel, attnum)
-#define RIAttCollation(rel, attnum) attnumCollationId(rel, attnum)
+#define RIAttName(rel, attphysnum)	NameStr(*attnumAttName(rel, attphysnum))
+#define RIAttType(rel, attphysnum)	attnumTypeId(rel, attphysnum)
+#define RIAttCollation(rel, attphysnum) attnumCollationId(rel, attphysnum)
 
 #define RI_TRIGTYPE_INSERT 1
 #define RI_TRIGTYPE_UPDATE 2
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index c3937a60fd..837dc6b20d 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -1348,7 +1348,7 @@ pg_get_indexdef_worker(Oid indexrelid, int colno,
 	sep = "";
 	for (keyno = 0; keyno < idxrec->indnatts; keyno++)
 	{
-		AttrNumber	attnum = idxrec->indkey.values[keyno];
+		AttrNumber	attphysnum = idxrec->indkey.values[keyno];
 		Oid			keycoltype;
 		Oid			keycolcollation;
 
@@ -1369,16 +1369,16 @@ pg_get_indexdef_worker(Oid indexrelid, int colno,
 			appendStringInfoString(&buf, sep);
 		sep = ", ";
 
-		if (attnum != 0)
+		if (attphysnum != 0)
 		{
 			/* Simple index column */
 			char	   *attname;
 			int32		keycoltypmod;
 
-			attname = get_attname(indrelid, attnum, false);
+			attname = get_attname(indrelid, attphysnum, false);
 			if (!colno || colno == keyno + 1)
 				appendStringInfoString(&buf, quote_identifier(attname));
-			get_atttypetypmodcoll(indrelid, attnum,
+			get_atttypetypmodcoll(indrelid, attphysnum,
 								  &keycoltype, &keycoltypmod,
 								  &keycolcollation);
 		}
@@ -1744,13 +1744,13 @@ pg_get_statisticsobj_worker(Oid statextid, bool columns_only, bool missing_ok)
 	/* decode simple column references */
 	for (colno = 0; colno < statextrec->stxkeys.dim1; colno++)
 	{
-		AttrNumber	attnum = statextrec->stxkeys.values[colno];
+		AttrNumber	attphysnum = statextrec->stxkeys.values[colno];
 		char	   *attname;
 
 		if (colno > 0)
 			appendStringInfoString(&buf, ", ");
 
-		attname = get_attname(statextrec->stxrelid, attnum, false);
+		attname = get_attname(statextrec->stxrelid, attphysnum, false);
 
 		appendStringInfoString(&buf, quote_identifier(attname));
 	}
@@ -1990,22 +1990,22 @@ pg_get_partkeydef_worker(Oid relid, int prettyFlags,
 	sep = "";
 	for (keyno = 0; keyno < form->partnatts; keyno++)
 	{
-		AttrNumber	attnum = form->partattrs.values[keyno];
+		AttrNumber	attphysnum = form->partattrs.values[keyno];
 		Oid			keycoltype;
 		Oid			keycolcollation;
 		Oid			partcoll;
 
 		appendStringInfoString(&buf, sep);
 		sep = ", ";
-		if (attnum != 0)
+		if (attphysnum != 0)
 		{
 			/* Simple attribute reference */
 			char	   *attname;
 			int32		keycoltypmod;
 
-			attname = get_attname(relid, attnum, false);
+			attname = get_attname(relid, attphysnum, false);
 			appendStringInfoString(&buf, quote_identifier(attname));
-			get_atttypetypmodcoll(relid, attnum,
+			get_atttypetypmodcoll(relid, attphysnum,
 								  &keycoltype, &keycoltypmod,
 								  &keycolcollation);
 		}
@@ -2798,7 +2798,7 @@ pg_get_serial_sequence(PG_FUNCTION_ARGS)
 	RangeVar   *tablerv;
 	Oid			tableOid;
 	char	   *column;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	Oid			sequenceId = InvalidOid;
 	Relation	depRel;
 	ScanKeyData key[3];
@@ -2812,8 +2812,8 @@ pg_get_serial_sequence(PG_FUNCTION_ARGS)
 	/* Get the number of the column */
 	column = text_to_cstring(columnname);
 
-	attnum = get_attnum(tableOid, column);
-	if (attnum == InvalidAttrNumber)
+	attphysnum = get_attphysnum(tableOid, column);
+	if (attphysnum == InvalidAttrNumber)
 		ereport(ERROR,
 				(errcode(ERRCODE_UNDEFINED_COLUMN),
 				 errmsg("column \"%s\" of relation \"%s\" does not exist",
@@ -2833,7 +2833,7 @@ pg_get_serial_sequence(PG_FUNCTION_ARGS)
 	ScanKeyInit(&key[2],
 				Anum_pg_depend_refobjsubid,
 				BTEqualStrategyNumber, F_INT4EQ,
-				Int32GetDatum(attnum));
+				Int32GetDatum(attphysnum));
 
 	scan = systable_beginscan(depRel, DependReferenceIndexId, true,
 							  NULL, 3, key);
@@ -4595,7 +4595,7 @@ set_join_column_names(deparse_namespace *dpns, RangeTblEntry *rte,
 	 * added since parse time must be inserted in the right places.  This code
 	 * must match the parser, which will order a join's columns as merged
 	 * columns first (in USING-clause order), then non-merged columns from the
-	 * left input (in attnum order), then non-merged columns from the right
+	 * left input (in attphysnum order), then non-merged columns from the right
 	 * input (ditto).  If one of the inputs is itself a join, its columns will
 	 * be ordered according to the same rule, which means newly-added columns
 	 * might not be at the end.  We can figure out what's what by consulting
@@ -7118,7 +7118,7 @@ get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context)
 {
 	StringInfo	buf = context->buf;
 	RangeTblEntry *rte;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	int			netlevelsup;
 	deparse_namespace *dpns;
 	int			varno;
@@ -7209,7 +7209,7 @@ get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context)
 		rte = rt_fetch(varno, dpns->rtable);
 		refname = (char *) list_nth(dpns->rtable_names, varno - 1);
 		colinfo = deparse_columns_fetch(varno, dpns);
-		attnum = varattno;
+		attphysnum = varattno;
 	}
 	else
 	{
@@ -7230,16 +7230,16 @@ get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context)
 	 * we'll have set dpns->inner_plan to reference the child plan node.
 	 */
 	if ((rte->rtekind == RTE_SUBQUERY || rte->rtekind == RTE_CTE) &&
-		attnum > list_length(rte->eref->colnames) &&
+		attphysnum > list_length(rte->eref->colnames) &&
 		dpns->inner_plan)
 	{
 		TargetEntry *tle;
 		deparse_namespace save_dpns;
 
-		tle = get_tle_by_resno(dpns->inner_tlist, attnum);
+		tle = get_tle_by_resno(dpns->inner_tlist, attphysnum);
 		if (!tle)
-			elog(ERROR, "invalid attnum %d for relation \"%s\"",
-				 attnum, rte->eref->aliasname);
+			elog(ERROR, "invalid attphysnum %d for relation \"%s\"",
+				 attphysnum, rte->eref->aliasname);
 
 		Assert(netlevelsup == 0);
 		push_child_plan(dpns, dpns->inner_plan, &save_dpns);
@@ -7274,11 +7274,11 @@ get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context)
 	{
 		if (rte->joinaliasvars == NIL)
 			elog(ERROR, "cannot decompile join alias var in plan tree");
-		if (attnum > 0)
+		if (attphysnum > 0)
 		{
 			Var		   *aliasvar;
 
-			aliasvar = (Var *) list_nth(rte->joinaliasvars, attnum - 1);
+			aliasvar = (Var *) list_nth(rte->joinaliasvars, attphysnum - 1);
 			/* we intentionally don't strip implicit coercions here */
 			if (aliasvar && IsA(aliasvar, Var))
 			{
@@ -7295,23 +7295,23 @@ get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context)
 		Assert(refname == NULL);
 	}
 
-	if (attnum == InvalidAttrNumber)
+	if (attphysnum == InvalidAttrNumber)
 		attname = NULL;
-	else if (attnum > 0)
+	else if (attphysnum > 0)
 	{
 		/* Get column name to use from the colinfo struct */
-		if (attnum > colinfo->num_cols)
-			elog(ERROR, "invalid attnum %d for relation \"%s\"",
-				 attnum, rte->eref->aliasname);
-		attname = colinfo->colnames[attnum - 1];
+		if (attphysnum > colinfo->num_cols)
+			elog(ERROR, "invalid attphysnum %d for relation \"%s\"",
+				 attphysnum, rte->eref->aliasname);
+		attname = colinfo->colnames[attphysnum - 1];
 		if (attname == NULL)	/* dropped column? */
-			elog(ERROR, "invalid attnum %d for relation \"%s\"",
-				 attnum, rte->eref->aliasname);
+			elog(ERROR, "invalid attphysnum %d for relation \"%s\"",
+				 attphysnum, rte->eref->aliasname);
 	}
 	else
 	{
 		/* System column - name is fixed, get it from the catalog */
-		attname = get_rte_attribute_name(rte, attnum);
+		attname = get_rte_attribute_name(rte, attphysnum);
 	}
 
 	if (refname && (context->varprefix || attname == NULL))
@@ -7474,7 +7474,7 @@ get_name_for_var_field(Var *var, int fieldno,
 					   int levelsup, deparse_context *context)
 {
 	RangeTblEntry *rte;
-	AttrNumber	attnum;
+	AttrNumber	attphysnum;
 	int			netlevelsup;
 	deparse_namespace *dpns;
 	int			varno;
@@ -7566,7 +7566,7 @@ get_name_for_var_field(Var *var, int fieldno,
 	if (varno >= 1 && varno <= list_length(dpns->rtable))
 	{
 		rte = rt_fetch(varno, dpns->rtable);
-		attnum = varattno;
+		attphysnum = varattno;
 	}
 	else if (varno == OUTER_VAR && dpns->outer_tlist)
 	{
@@ -7628,7 +7628,7 @@ get_name_for_var_field(Var *var, int fieldno,
 		return NULL;			/* keep compiler quiet */
 	}
 
-	if (attnum == InvalidAttrNumber)
+	if (attphysnum == InvalidAttrNumber)
 	{
 		/* Var is whole-row reference to RTE, so select the right field */
 		return get_rte_attribute_name(rte, fieldno);
@@ -7662,11 +7662,11 @@ get_name_for_var_field(Var *var, int fieldno,
 				if (rte->subquery)
 				{
 					TargetEntry *ste = get_tle_by_resno(rte->subquery->targetList,
-														attnum);
+														attphysnum);
 
 					if (ste == NULL || ste->resjunk)
 						elog(ERROR, "subquery %s does not have attribute %d",
-							 rte->eref->aliasname, attnum);
+							 rte->eref->aliasname, attphysnum);
 					expr = (Node *) ste->expr;
 					if (IsA(expr, Var))
 					{
@@ -7711,10 +7711,10 @@ get_name_for_var_field(Var *var, int fieldno,
 					if (!dpns->inner_plan)
 						elog(ERROR, "failed to find plan for subquery %s",
 							 rte->eref->aliasname);
-					tle = get_tle_by_resno(dpns->inner_tlist, attnum);
+					tle = get_tle_by_resno(dpns->inner_tlist, attphysnum);
 					if (!tle)
 						elog(ERROR, "bogus varattno for subquery var: %d",
-							 attnum);
+							 attphysnum);
 					Assert(netlevelsup == 0);
 					push_child_plan(dpns, dpns->inner_plan, &save_dpns);
 
@@ -7730,8 +7730,8 @@ get_name_for_var_field(Var *var, int fieldno,
 			/* Join RTE --- recursively inspect the alias variable */
 			if (rte->joinaliasvars == NIL)
 				elog(ERROR, "cannot decompile join alias var in plan tree");
-			Assert(attnum > 0 && attnum <= list_length(rte->joinaliasvars));
-			expr = (Node *) list_nth(rte->joinaliasvars, attnum - 1);
+			Assert(attphysnum > 0 && attphysnum <= list_length(rte->joinaliasvars));
+			expr = (Node *) list_nth(rte->joinaliasvars, attphysnum - 1);
 			Assert(expr != NULL);
 			/* we intentionally don't strip implicit coercions here */
 			if (IsA(expr, Var))
@@ -7778,11 +7778,11 @@ get_name_for_var_field(Var *var, int fieldno,
 				{
 					Query	   *ctequery = (Query *) cte->ctequery;
 					TargetEntry *ste = get_tle_by_resno(GetCTETargetList(cte),
-														attnum);
+														attphysnum);
 
 					if (ste == NULL || ste->resjunk)
 						elog(ERROR, "subquery %s does not have attribute %d",
-							 rte->eref->aliasname, attnum);
+							 rte->eref->aliasname, attphysnum);
 					expr = (Node *) ste->expr;
 					if (IsA(expr, Var))
 					{
@@ -7832,10 +7832,10 @@ get_name_for_var_field(Var *var, int fieldno,
 					if (!dpns->inner_plan)
 						elog(ERROR, "failed to find plan for CTE %s",
 							 rte->eref->aliasname);
-					tle = get_tle_by_resno(dpns->inner_tlist, attnum);
+					tle = get_tle_by_resno(dpns->inner_tlist, attphysnum);
 					if (!tle)
 						elog(ERROR, "bogus varattno for subquery var: %d",
-							 attnum);
+							 attphysnum);
 					Assert(netlevelsup == 0);
 					push_child_plan(dpns, dpns->inner_plan, &save_dpns);
 
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index fa1f589fad..04702b3ccc 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -3973,24 +3973,24 @@ estimate_multivariate_ndistinct(PlannerInfo *root, RelOptInfo *rel,
 		{
 			ListCell   *lc3;
 			GroupVarInfo *varinfo = (GroupVarInfo *) lfirst(lc2);
-			AttrNumber	attnum;
+			AttrNumber	attphysnum;
 
 			Assert(varinfo->rel == rel);
 
 			/* simple Var, search in statistics keys directly */
 			if (IsA(varinfo->var, Var))
 			{
-				attnum = ((Var *) varinfo->var)->varattno;
+				attphysnum = ((Var *) varinfo->var)->varattno;
 
 				/*
 				 * Ignore system attributes - we don't support statistics on
 				 * them, so can't match them (and it'd fail as the values are
 				 * negative).
 				 */
-				if (!AttrNumberIsForUserDefinedAttr(attnum))
+				if (!AttrNumberIsForUserDefinedAttr(attphysnum))
 					continue;
 
-				if (bms_is_member(attnum, info->keys))
+				if (bms_is_member(attphysnum, info->keys))
 					nshared_vars++;
 
 				continue;
@@ -4077,25 +4077,25 @@ estimate_multivariate_ndistinct(PlannerInfo *root, RelOptInfo *rel,
 			 */
 			if (IsA(varinfo->var, Var))
 			{
-				AttrNumber	attnum = ((Var *) varinfo->var)->varattno;
+				AttrNumber	attphysnum = ((Var *) varinfo->var)->varattno;
 
 				/*
 				 * Ignore expressions on system attributes. Can't rely on the
 				 * bms check for negative values.
 				 */
-				if (!AttrNumberIsForUserDefinedAttr(attnum))
+				if (!AttrNumberIsForUserDefinedAttr(attphysnum))
 					continue;
 
 				/* Is the variable covered by the statistics object? */
-				if (!bms_is_member(attnum, matched_info->keys))
+				if (!bms_is_member(attphysnum, matched_info->keys))
 					continue;
 
-				attnum = attnum + attnum_offset;
+				attphysnum = attphysnum + attnum_offset;
 
 				/* ensure sufficient offset */
-				Assert(AttrNumberIsForUserDefinedAttr(attnum));
+				Assert(AttrNumberIsForUserDefinedAttr(attphysnum));
 
-				matched = bms_add_member(matched, attnum);
+				matched = bms_add_member(matched, attphysnum);
 
 				found = true;
 			}
@@ -4116,14 +4116,14 @@ estimate_multivariate_ndistinct(PlannerInfo *root, RelOptInfo *rel,
 
 				if (equal(varinfo->var, expr))
 				{
-					AttrNumber	attnum = -(idx + 1);
+					AttrNumber	attphysnum = -(idx + 1);
 
-					attnum = attnum + attnum_offset;
+					attphysnum = attphysnum + attnum_offset;
 
 					/* ensure sufficient offset */
-					Assert(AttrNumberIsForUserDefinedAttr(attnum));
+					Assert(AttrNumberIsForUserDefinedAttr(attphysnum));
 
-					matched = bms_add_member(matched, attnum);
+					matched = bms_add_member(matched, attphysnum);
 
 					/* there should be just one matching expression */
 					break;
@@ -4148,15 +4148,15 @@ estimate_multivariate_ndistinct(PlannerInfo *root, RelOptInfo *rel,
 			/* check that all item attributes/expressions fit the match */
 			for (j = 0; j < tmpitem->nattributes; j++)
 			{
-				AttrNumber	attnum = tmpitem->attributes[j];
+				AttrNumber	attphysnum = tmpitem->attributes[j];
 
 				/*
 				 * Thanks to how we constructed the matched bitmap above, we
 				 * can just offset all attnums the same way.
 				 */
-				attnum = attnum + attnum_offset;
+				attphysnum = attphysnum + attnum_offset;
 
-				if (!bms_is_member(attnum, matched))
+				if (!bms_is_member(attphysnum, matched))
 				{
 					/* nah, it's not this item */
 					item = NULL;
@@ -4189,28 +4189,28 @@ estimate_multivariate_ndistinct(PlannerInfo *root, RelOptInfo *rel,
 			/*
 			 * Let's look at plain variables first, because it's the most
 			 * common case and the check is quite cheap. We can simply get the
-			 * attnum and check (with an offset) matched bitmap.
+			 * attphysnum and check (with an offset) matched bitmap.
 			 */
 			if (IsA(varinfo->var, Var))
 			{
-				AttrNumber	attnum = ((Var *) varinfo->var)->varattno;
+				AttrNumber	attphysnum = ((Var *) varinfo->var)->varattno;
 
 				/*
 				 * If it's a system attribute, we're done. We don't support
 				 * extended statistics on system attributes, so it's clearly
 				 * not matched. Just keep the expression and continue.
 				 */
-				if (!AttrNumberIsForUserDefinedAttr(attnum))
+				if (!AttrNumberIsForUserDefinedAttr(attphysnum))
 				{
 					newlist = lappend(newlist, varinfo);
 					continue;
 				}
 
 				/* apply the same offset as above */
-				attnum += attnum_offset;
+				attphysnum += attnum_offset;
 
 				/* if it's not matched, keep the varinfo */
-				if (!bms_is_member(attnum, matched))
+				if (!bms_is_member(attphysnum, matched))
 					newlist = lappend(newlist, varinfo);
 
 				/* The rest of the loop deals with complex expressions. */
@@ -7804,14 +7804,14 @@ brincostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 	foreach(l, path->indexclauses)
 	{
 		IndexClause *iclause = lfirst_node(IndexClause, l);
-		AttrNumber	attnum = index->indexkeys[iclause->indexcol];
+		AttrNumber	attphysnum = index->indexkeys[iclause->indexcol];
 
 		/* attempt to lookup stats in relation for this index column */
-		if (attnum != 0)
+		if (attphysnum != 0)
 		{
 			/* Simple variable -- look to stats for the underlying table */
 			if (get_relation_stats_hook &&
-				(*get_relation_stats_hook) (root, rte, attnum, &vardata))
+				(*get_relation_stats_hook) (root, rte, attphysnum, &vardata))
 			{
 				/*
 				 * The hook took control of acquiring a stats tuple.  If it
@@ -7826,7 +7826,7 @@ brincostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 				vardata.statsTuple =
 					SearchSysCache3(STATRELATTINH,
 									ObjectIdGetDatum(rte->relid),
-									Int16GetDatum(attnum),
+									Int16GetDatum(attphysnum),
 									BoolGetDatum(false));
 				vardata.freefunc = ReleaseSysCache;
 			}
@@ -7838,11 +7838,11 @@ brincostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 			 * see if there's any stats for it.
 			 */
 
-			/* get the attnum from the 0-based index. */
-			attnum = iclause->indexcol + 1;
+			/* get the attphysnum from the 0-based index. */
+			attphysnum = iclause->indexcol + 1;
 
 			if (get_index_stats_hook &&
-				(*get_index_stats_hook) (root, index->indexoid, attnum, &vardata))
+				(*get_index_stats_hook) (root, index->indexoid, attphysnum, &vardata))
 			{
 				/*
 				 * The hook took control of acquiring a stats tuple.  If it
@@ -7856,7 +7856,7 @@ brincostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 			{
 				vardata.statsTuple = SearchSysCache3(STATRELATTINH,
 													 ObjectIdGetDatum(index->indexoid),
-													 Int16GetDatum(attnum),
+													 Int16GetDatum(attphysnum),
 													 BoolGetDatum(false));
 				vardata.freefunc = ReleaseSysCache;
 			}
diff --git a/src/backend/utils/cache/attoptcache.c b/src/backend/utils/cache/attoptcache.c
index 9e252a0891..0c9893ca95 100644
--- a/src/backend/utils/cache/attoptcache.c
+++ b/src/backend/utils/cache/attoptcache.c
@@ -27,11 +27,11 @@
 /* Hash table for information about each attribute's options */
 static HTAB *AttoptCacheHash = NULL;
 
-/* attrelid and attnum form the lookup key, and must appear first */
+/* attrelid and attphysnum form the lookup key, and must appear first */
 typedef struct
 {
 	Oid			attrelid;
-	int			attnum;
+	int			attphysnum;
 } AttoptCacheKey;
 
 typedef struct
@@ -90,7 +90,7 @@ InitializeAttoptCache(void)
 		CreateCacheMemoryContext();
 
 	/* Watch for invalidation events. */
-	CacheRegisterSyscacheCallback(ATTNUM,
+	CacheRegisterSyscacheCallback(ATTPHYSNUM,
 								  InvalidateAttoptCacheCallback,
 								  (Datum) 0);
 }
@@ -100,7 +100,7 @@ InitializeAttoptCache(void)
  *		Fetch attribute options for a specified table OID.
  */
 AttributeOpts *
-get_attribute_options(Oid attrelid, int attnum)
+get_attribute_options(Oid attrelid, int attphysnum)
 {
 	AttoptCacheKey key;
 	AttoptCacheEntry *attopt;
@@ -112,7 +112,7 @@ get_attribute_options(Oid attrelid, int attnum)
 		InitializeAttoptCache();
 	memset(&key, 0, sizeof(key));	/* make sure any padding bits are unset */
 	key.attrelid = attrelid;
-	key.attnum = attnum;
+	key.attphysnum = attphysnum;
 	attopt =
 		(AttoptCacheEntry *) hash_search(AttoptCacheHash,
 										 (void *) &key,
@@ -124,9 +124,9 @@ get_attribute_options(Oid attrelid, int attnum)
 	{
 		AttributeOpts *opts;
 
-		tp = SearchSysCache2(ATTNUM,
+		tp = SearchSysCache2(ATTPHYSNUM,
 							 ObjectIdGetDatum(attrelid),
-							 Int16GetDatum(attnum));
+							 Int16GetDatum(attphysnum));
 
 		/*
 		 * If we don't find a valid HeapTuple, it must mean someone has
@@ -140,7 +140,7 @@ get_attribute_options(Oid attrelid, int attnum)
 			Datum		datum;
 			bool		isNull;
 
-			datum = SysCacheGetAttr(ATTNUM,
+			datum = SysCacheGetAttr(ATTPHYSNUM,
 									tp,
 									Anum_pg_attribute_attoptions,
 									&isNull);
diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c
index 6ae7c1f50b..9bf99c113b 100644
--- a/src/backend/utils/cache/catcache.c
+++ b/src/backend/utils/cache/catcache.c
@@ -1909,13 +1909,13 @@ CatCacheFreeKeys(TupleDesc tupdesc, int nkeys, int *attnos, Datum *keys)
 
 	for (i = 0; i < nkeys; i++)
 	{
-		int			attnum = attnos[i];
+		int			attphysnum = attnos[i];
 		Form_pg_attribute att;
 
 		/* system attribute are not supported in caches */
-		Assert(attnum > 0);
+		Assert(attphysnum > 0);
 
-		att = TupleDescAttr(tupdesc, attnum - 1);
+		att = TupleDescAttr(tupdesc, attphysnum - 1);
 
 		if (!att->attbyval)
 			pfree(DatumGetPointer(keys[i]));
@@ -1940,8 +1940,8 @@ CatCacheCopyKeys(TupleDesc tupdesc, int nkeys, int *attnos,
 
 	for (i = 0; i < nkeys; i++)
 	{
-		int			attnum = attnos[i];
-		Form_pg_attribute att = TupleDescAttr(tupdesc, attnum - 1);
+		int			attphysnum = attnos[i];
+		Form_pg_attribute att = TupleDescAttr(tupdesc, attphysnum - 1);
 		Datum		src = srckeys[i];
 		NameData	srcname;
 
diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index 1b7e11b93e..721fb194e7 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -822,12 +822,12 @@ get_opfamily_proc(Oid opfamily, Oid lefttype, Oid righttype, int16 procnum)
  * otherwise a not-intended-for-user-consumption error is thrown.
  */
 char *
-get_attname(Oid relid, AttrNumber attnum, bool missing_ok)
+get_attname(Oid relid, AttrNumber attphysnum, bool missing_ok)
 {
 	HeapTuple	tp;
 
-	tp = SearchSysCache2(ATTNUM,
-						 ObjectIdGetDatum(relid), Int16GetDatum(attnum));
+	tp = SearchSysCache2(ATTPHYSNUM,
+						 ObjectIdGetDatum(relid), Int16GetDatum(attphysnum));
 	if (HeapTupleIsValid(tp))
 	{
 		Form_pg_attribute att_tup = (Form_pg_attribute) GETSTRUCT(tp);
@@ -840,7 +840,7 @@ get_attname(Oid relid, AttrNumber attnum, bool missing_ok)
 
 	if (!missing_ok)
 		elog(ERROR, "cache lookup failed for attribute %d of relation %u",
-			 attnum, relid);
+			 attphysnum, relid);
 	return NULL;
 }
 
@@ -848,12 +848,12 @@ get_attname(Oid relid, AttrNumber attnum, bool missing_ok)
  * get_attnum
  *
  *		Given the relation id and the attribute name,
- *		return the "attnum" field from the attribute relation.
+ *		return the "attphysnum" field from the attribute relation.
  *
  *		Returns InvalidAttrNumber if the attr doesn't exist (or is dropped).
  */
 AttrNumber
-get_attnum(Oid relid, const char *attname)
+get_attphysnum(Oid relid, const char *attname)
 {
 	HeapTuple	tp;
 
@@ -863,7 +863,7 @@ get_attnum(Oid relid, const char *attname)
 		Form_pg_attribute att_tup = (Form_pg_attribute) GETSTRUCT(tp);
 		AttrNumber	result;
 
-		result = att_tup->attnum;
+		result = att_tup->attphysnum;
 		ReleaseSysCache(tp);
 		return result;
 	}
@@ -880,18 +880,18 @@ get_attnum(Oid relid, const char *attname)
  *		Errors if not found.
  */
 int
-get_attstattarget(Oid relid, AttrNumber attnum)
+get_attstattarget(Oid relid, AttrNumber attphysnum)
 {
 	HeapTuple	tp;
 	Form_pg_attribute att_tup;
 	int			result;
 
-	tp = SearchSysCache2(ATTNUM,
+	tp = SearchSysCache2(ATTPHYSNUM,
 						 ObjectIdGetDatum(relid),
-						 Int16GetDatum(attnum));
+						 Int16GetDatum(attphysnum));
 	if (!HeapTupleIsValid(tp))
 		elog(ERROR, "cache lookup failed for attribute %d of relation %u",
-			 attnum, relid);
+			 attphysnum, relid);
 	att_tup = (Form_pg_attribute) GETSTRUCT(tp);
 	result = att_tup->attstattarget;
 	ReleaseSysCache(tp);
@@ -910,18 +910,18 @@ get_attstattarget(Oid relid, AttrNumber attnum)
  *		Boolean test.
  */
 char
-get_attgenerated(Oid relid, AttrNumber attnum)
+get_attgenerated(Oid relid, AttrNumber attphysnum)
 {
 	HeapTuple	tp;
 	Form_pg_attribute att_tup;
 	char		result;
 
-	tp = SearchSysCache2(ATTNUM,
+	tp = SearchSysCache2(ATTPHYSNUM,
 						 ObjectIdGetDatum(relid),
-						 Int16GetDatum(attnum));
+						 Int16GetDatum(attphysnum));
 	if (!HeapTupleIsValid(tp))
 		elog(ERROR, "cache lookup failed for attribute %d of relation %u",
-			 attnum, relid);
+			 attphysnum, relid);
 	att_tup = (Form_pg_attribute) GETSTRUCT(tp);
 	result = att_tup->attgenerated;
 	ReleaseSysCache(tp);
@@ -935,13 +935,13 @@ get_attgenerated(Oid relid, AttrNumber attnum)
  *		return the attribute type OID.
  */
 Oid
-get_atttype(Oid relid, AttrNumber attnum)
+get_atttype(Oid relid, AttrNumber attphysnum)
 {
 	HeapTuple	tp;
 
-	tp = SearchSysCache2(ATTNUM,
+	tp = SearchSysCache2(ATTPHYSNUM,
 						 ObjectIdGetDatum(relid),
-						 Int16GetDatum(attnum));
+						 Int16GetDatum(attphysnum));
 	if (HeapTupleIsValid(tp))
 	{
 		Form_pg_attribute att_tup = (Form_pg_attribute) GETSTRUCT(tp);
@@ -965,18 +965,18 @@ get_atttype(Oid relid, AttrNumber attnum)
  * raises an error if it can't obtain the information.
  */
 void
-get_atttypetypmodcoll(Oid relid, AttrNumber attnum,
+get_atttypetypmodcoll(Oid relid, AttrNumber attphysnum,
 					  Oid *typid, int32 *typmod, Oid *collid)
 {
 	HeapTuple	tp;
 	Form_pg_attribute att_tup;
 
-	tp = SearchSysCache2(ATTNUM,
+	tp = SearchSysCache2(ATTPHYSNUM,
 						 ObjectIdGetDatum(relid),
-						 Int16GetDatum(attnum));
+						 Int16GetDatum(attphysnum));
 	if (!HeapTupleIsValid(tp))
 		elog(ERROR, "cache lookup failed for attribute %d of relation %u",
-			 attnum, relid);
+			 attphysnum, relid);
 	att_tup = (Form_pg_attribute) GETSTRUCT(tp);
 
 	*typid = att_tup->atttypid;
@@ -992,20 +992,20 @@ get_atttypetypmodcoll(Oid relid, AttrNumber attnum,
  *		return the attribute options text[] datum, if any.
  */
 Datum
-get_attoptions(Oid relid, int16 attnum)
+get_attoptions(Oid relid, int16 attphysnum)
 {
 	HeapTuple	tuple;
 	Datum		attopts;
 	Datum		result;
 	bool		isnull;
 
-	tuple = SearchSysCache2(ATTNUM,
+	tuple = SearchSysCache2(ATTPHYSNUM,
 							ObjectIdGetDatum(relid),
-							Int16GetDatum(attnum));
+							Int16GetDatum(attphysnum));
 
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "cache lookup failed for attribute %d of relation %u",
-			 attnum, relid);
+			 attphysnum, relid);
 
 	attopts = SysCacheGetAttr(ATTNAME, tuple, Anum_pg_attribute_attoptions,
 							  &isnull);
@@ -3112,20 +3112,20 @@ getSubscriptingRoutines(Oid typid, Oid *typelemp)
  * plug-ins to control the result.
  */
 int32
-get_attavgwidth(Oid relid, AttrNumber attnum)
+get_attavgwidth(Oid relid, AttrNumber attphysnum)
 {
 	HeapTuple	tp;
 	int32		stawidth;
 
 	if (get_attavgwidth_hook)
 	{
-		stawidth = (*get_attavgwidth_hook) (relid, attnum);
+		stawidth = (*get_attavgwidth_hook) (relid, attphysnum);
 		if (stawidth > 0)
 			return stawidth;
 	}
 	tp = SearchSysCache3(STATRELATTINH,
 						 ObjectIdGetDatum(relid),
-						 Int16GetDatum(attnum),
+						 Int16GetDatum(attphysnum),
 						 BoolGetDatum(false));
 	if (HeapTupleIsValid(tp))
 	{
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 0e8fda97f8..8a98060956 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -537,7 +537,7 @@ RelationBuildTupleDesc(Relation relation)
 	constr->has_generated_stored = false;
 
 	/*
-	 * Form a scan key that selects only user attributes (attnum > 0).
+	 * Form a scan key that selects only user attributes (attphysnum > 0).
 	 * (Eliminating system attribute rows at the index level is lots faster
 	 * than fetching them.)
 	 */
@@ -546,7 +546,7 @@ RelationBuildTupleDesc(Relation relation)
 				BTEqualStrategyNumber, F_OIDEQ,
 				ObjectIdGetDatum(RelationGetRelid(relation)));
 	ScanKeyInit(&skey[1],
-				Anum_pg_attribute_attnum,
+				Anum_pg_attribute_attphysnum,
 				BTGreaterStrategyNumber, F_INT2GT,
 				Int16GetDatum(0));
 
@@ -557,7 +557,7 @@ RelationBuildTupleDesc(Relation relation)
 	 */
 	pg_attribute_desc = table_open(AttributeRelationId, AccessShareLock);
 	pg_attribute_scan = systable_beginscan(pg_attribute_desc,
-										   AttributeRelidNumIndexId,
+										   AttributeRelidPhysNumIndexId,
 										   criticalRelcachesBuilt,
 										   NULL,
 										   2, skey);
@@ -570,16 +570,16 @@ RelationBuildTupleDesc(Relation relation)
 	while (HeapTupleIsValid(pg_attribute_tuple = systable_getnext(pg_attribute_scan)))
 	{
 		Form_pg_attribute attp;
-		int			attnum;
+		int			attphysnum;
 
 		attp = (Form_pg_attribute) GETSTRUCT(pg_attribute_tuple);
 
-		attnum = attp->attnum;
-		if (attnum <= 0 || attnum > RelationGetNumberOfAttributes(relation))
+		attphysnum = attp->attphysnum;
+		if (attphysnum <= 0 || attphysnum > RelationGetNumberOfAttributes(relation))
 			elog(ERROR, "invalid attribute number %d for relation \"%s\"",
-				 attp->attnum, RelationGetRelationName(relation));
+				 attp->attphysnum, RelationGetRelationName(relation));
 
-		memcpy(TupleDescAttr(relation->rd_att, attnum - 1),
+		memcpy(TupleDescAttr(relation->rd_att, attphysnum - 1),
 			   attp,
 			   ATTRIBUTE_FIXED_PART_SIZE);
 
@@ -628,18 +628,18 @@ RelationBuildTupleDesc(Relation relation)
 				if (attp->attbyval)
 				{
 					/* for copy by val just copy the datum direct */
-					attrmiss[attnum - 1].am_value = missval;
+					attrmiss[attphysnum - 1].am_value = missval;
 				}
 				else
 				{
 					/* otherwise copy in the correct context */
 					oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
-					attrmiss[attnum - 1].am_value = datumCopy(missval,
+					attrmiss[attphysnum - 1].am_value = datumCopy(missval,
 															  attp->attbyval,
 															  attp->attlen);
 					MemoryContextSwitchTo(oldcxt);
 				}
-				attrmiss[attnum - 1].am_present = true;
+				attrmiss[attphysnum - 1].am_present = true;
 			}
 		}
 		need--;
@@ -4046,7 +4046,7 @@ RelationCacheInitializePhase3(void)
 	{
 		load_critical_index(ClassOidIndexId,
 							RelationRelationId);
-		load_critical_index(AttributeRelidNumIndexId,
+		load_critical_index(AttributeRelidPhysNumIndexId,
 							AttributeRelationId);
 		load_critical_index(IndexRelidIndexId,
 							IndexRelationId);
@@ -5708,21 +5708,21 @@ RelationGetIndexRawAttOptions(Relation indexrel)
 	Oid			indexrelid = RelationGetRelid(indexrel);
 	int16		natts = RelationGetNumberOfAttributes(indexrel);
 	Datum	   *options = NULL;
-	int16		attnum;
+	int16		attphysnum;
 
-	for (attnum = 1; attnum <= natts; attnum++)
+	for (attphysnum = 1; attphysnum <= natts; attphysnum++)
 	{
 		if (indexrel->rd_indam->amoptsprocnum == 0)
 			continue;
 
-		if (!OidIsValid(index_getprocid(indexrel, attnum,
+		if (!OidIsValid(index_getprocid(indexrel, attphysnum,
 										indexrel->rd_indam->amoptsprocnum)))
 			continue;
 
 		if (!options)
 			options = palloc0(sizeof(Datum) * natts);
 
-		options[attnum - 1] = get_attoptions(indexrelid, attnum);
+		options[attphysnum - 1] = get_attoptions(indexrelid, attphysnum);
 	}
 
 	return options;
@@ -5767,7 +5767,7 @@ RelationGetIndexAttOptions(Relation relation, bool copy)
 
 	for (i = 0; i < natts; i++)
 	{
-		if (criticalRelcachesBuilt && relid != AttributeRelidNumIndexId)
+		if (criticalRelcachesBuilt && relid != AttributeRelidPhysNumIndexId)
 		{
 			Datum		attoptions = get_attoptions(relid, i + 1);
 
@@ -5827,16 +5827,16 @@ errtable(Relation rel)
  * easier and less error-prone than getting the column name for themselves.
  */
 int
-errtablecol(Relation rel, int attnum)
+errtablecol(Relation rel, int attphysnum)
 {
 	TupleDesc	reldesc = RelationGetDescr(rel);
 	const char *colname;
 
 	/* Use reldesc if it's a user attribute, else consult the catalogs */
-	if (attnum > 0 && attnum <= reldesc->natts)
-		colname = NameStr(TupleDescAttr(reldesc, attnum - 1)->attname);
+	if (attphysnum > 0 && attphysnum <= reldesc->natts)
+		colname = NameStr(TupleDescAttr(reldesc, attphysnum - 1)->attname);
 	else
-		colname = get_attname(RelationGetRelid(rel), attnum, false);
+		colname = get_attname(RelationGetRelid(rel), attphysnum, false);
 
 	return errtablecolname(rel, colname);
 }
diff --git a/src/backend/utils/cache/syscache.c b/src/backend/utils/cache/syscache.c
index 1912b12146..9751ad6a22 100644
--- a/src/backend/utils/cache/syscache.c
+++ b/src/backend/utils/cache/syscache.c
@@ -200,12 +200,12 @@ static const struct cachedesc cacheinfo[] = {
 		},
 		32
 	},
-	{AttributeRelationId,		/* ATTNUM */
-		AttributeRelidNumIndexId,
+	{AttributeRelationId,		/* ATTPHYSNUM */
+		AttributeRelidPhysNumIndexId,
 		2,
 		{
 			Anum_pg_attribute_attrelid,
-			Anum_pg_attribute_attnum,
+			Anum_pg_attribute_attphysnum,
 			0,
 			0
 		},
@@ -1368,19 +1368,19 @@ SearchSysCacheExistsAttName(Oid relid, const char *attname)
 /*
  * SearchSysCacheAttNum
  *
- * This routine is equivalent to SearchSysCache on the ATTNUM cache,
+ * This routine is equivalent to SearchSysCache on the ATTPHYSNUM cache,
  * except that it will return NULL if the found attribute is marked
  * attisdropped.  This is convenient for callers that want to act as
  * though dropped attributes don't exist.
  */
 HeapTuple
-SearchSysCacheAttNum(Oid relid, int16 attnum)
+SearchSysCacheAttNum(Oid relid, int16 attphysnum)
 {
 	HeapTuple	tuple;
 
-	tuple = SearchSysCache2(ATTNUM,
+	tuple = SearchSysCache2(ATTPHYSNUM,
 							ObjectIdGetDatum(relid),
-							Int16GetDatum(attnum));
+							Int16GetDatum(attphysnum));
 	if (!HeapTupleIsValid(tuple))
 		return NULL;
 	if (((Form_pg_attribute) GETSTRUCT(tuple))->attisdropped)
@@ -1397,12 +1397,12 @@ SearchSysCacheAttNum(Oid relid, int16 attnum)
  * As above, an attisdropped-aware version of SearchSysCacheCopy.
  */
 HeapTuple
-SearchSysCacheCopyAttNum(Oid relid, int16 attnum)
+SearchSysCacheCopyAttNum(Oid relid, int16 attphysnum)
 {
 	HeapTuple	tuple,
 				newtuple;
 
-	tuple = SearchSysCacheAttNum(relid, attnum);
+	tuple = SearchSysCacheAttNum(relid, attphysnum);
 	if (!HeapTupleIsValid(tuple))
 		return NULL;
 	newtuple = heap_copytuple(tuple);
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index ed6de7ca94..b6fb9391e7 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -1612,7 +1612,7 @@ setup_privileges(FILE *cmdfd)
 		"    SELECT"
 		"        pg_class.oid,"
 		"        (SELECT oid FROM pg_class WHERE relname = 'pg_class'),"
-		"        pg_attribute.attnum,"
+		"        pg_attribute.attphysnum,"
 		"        pg_attribute.attacl,"
 		"        'i'"
 		"    FROM"
diff --git a/src/bin/pg_amcheck/pg_amcheck.c b/src/bin/pg_amcheck/pg_amcheck.c
index 3cff319f02..dc043f73ae 100644
--- a/src/bin/pg_amcheck/pg_amcheck.c
+++ b/src/bin/pg_amcheck/pg_amcheck.c
@@ -802,7 +802,7 @@ prepare_heap_command(PQExpBuffer sql, RelationInfo *rel, PGconn *conn)
 {
 	resetPQExpBuffer(sql);
 	appendPQExpBuffer(sql,
-					  "SELECT v.blkno, v.offnum, v.attnum, v.msg "
+					  "SELECT v.blkno, v.offnum, v.attphysnum, v.msg "
 					  "FROM pg_catalog.pg_class c, %s.verify_heapam("
 					  "\nrelation := c.oid, on_error_stop := %s, check_toast := %s, skip := '%s'",
 					  rel->datinfo->amcheck_schema,
@@ -1016,7 +1016,7 @@ verify_heap_slot_handler(PGresult *res, PGconn *conn, void *context)
 					   rel->datinfo->datname, rel->nspname, rel->relname,
 					   PQgetvalue(res, i, 0),	/* blkno */
 					   PQgetvalue(res, i, 1),	/* offnum */
-					   PQgetvalue(res, i, 2));	/* attnum */
+					   PQgetvalue(res, i, 2));	/* attphysnum */
 
 			else if (!PQgetisnull(res, i, 1))
 				printf(_("heap table \"%s.%s.%s\", block %s, offset %s:\n"),
diff --git a/src/bin/pg_amcheck/t/003_check.pl b/src/bin/pg_amcheck/t/003_check.pl
index 0cf67065d6..224287e6f5 100644
--- a/src/bin/pg_amcheck/t/003_check.pl
+++ b/src/bin/pg_amcheck/t/003_check.pl
@@ -172,7 +172,7 @@ for my $dbname (qw(db1 db2 db3))
 											 endblock bigint default null,
 											 blkno OUT bigint,
 											 offnum OUT integer,
-											 attnum OUT integer,
+											 attphysnum OUT integer,
 											 msg OUT text)
 		RETURNS SETOF record AS $$
 		BEGIN
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 7cc9c72e49..58e07f008c 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -4171,7 +4171,7 @@ getPublicationTables(Archive *fout, TableInfo tblinfo[], int numTables)
 							 "       FROM\n"
 							 "         pg_catalog.generate_series(0, pg_catalog.array_upper(pr.prattrs::pg_catalog.int2[], 1)) s,\n"
 							 "         pg_catalog.pg_attribute\n"
-							 "      WHERE attrelid = pr.prrelid AND attnum = prattrs[s])\n"
+							 "      WHERE attrelid = pr.prrelid AND attphysnum = prattrs[s])\n"
 							 "  ELSE NULL END) prattrs "
 							 "FROM pg_catalog.pg_publication_rel pr");
 	else
@@ -6719,11 +6719,11 @@ getIndexes(Archive *fout, TableInfo tblinfo[], int numTables)
 						  "inh.inhparent AS parentidx, "
 						  "i.indnkeyatts AS indnkeyatts, "
 						  "i.indnatts AS indnatts, "
-						  "(SELECT pg_catalog.array_agg(attnum ORDER BY attnum) "
+						  "(SELECT pg_catalog.array_agg(attphysnum ORDER BY attphysnum) "
 						  "  FROM pg_catalog.pg_attribute "
 						  "  WHERE attrelid = i.indexrelid AND "
 						  "    attstattarget >= 0) AS indstatcols, "
-						  "(SELECT pg_catalog.array_agg(attstattarget ORDER BY attnum) "
+						  "(SELECT pg_catalog.array_agg(attstattarget ORDER BY attphysnum) "
 						  "  FROM pg_catalog.pg_attribute "
 						  "  WHERE attrelid = i.indexrelid AND "
 						  "    attstattarget >= 0) AS indstatvals, ");
@@ -8130,7 +8130,7 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
 	appendPQExpBufferStr(q,
 						 "SELECT\n"
 						 "a.attrelid,\n"
-						 "a.attnum,\n"
+						 "a.attphysnum,\n"
 						 "a.attname,\n"
 						 "a.atttypmod,\n"
 						 "a.attstattarget,\n"
@@ -8188,8 +8188,8 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
 					  "JOIN pg_catalog.pg_attribute a ON (src.tbloid = a.attrelid) "
 					  "LEFT JOIN pg_catalog.pg_type t "
 					  "ON (a.atttypid = t.oid)\n"
-					  "WHERE a.attnum > 0::pg_catalog.int2\n"
-					  "ORDER BY a.attrelid, a.attnum",
+					  "WHERE a.attphysnum > 0::pg_catalog.int2\n"
+					  "ORDER BY a.attrelid, a.attphysnum",
 					  tbloids->data);
 
 	res = ExecuteSqlQuery(fout, q->data, PGRES_TUPLES_OK);
@@ -8197,7 +8197,7 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
 	ntups = PQntuples(res);
 
 	i_attrelid = PQfnumber(res, "attrelid");
-	i_attnum = PQfnumber(res, "attnum");
+	i_attnum = PQfnumber(res, "attphysnum");
 	i_attname = PQfnumber(res, "attname");
 	i_atttypname = PQfnumber(res, "atttypname");
 	i_atttypmod = PQfnumber(res, "atttypmod");
@@ -11010,7 +11010,7 @@ dumpCompositeType(Archive *fout, const TypeInfo *tyinfo)
 		 */
 		appendPQExpBufferStr(query,
 							 "PREPARE dumpCompositeType(pg_catalog.oid) AS\n"
-							 "SELECT a.attname, a.attnum, "
+							 "SELECT a.attname, a.attphysnum, "
 							 "pg_catalog.format_type(a.atttypid, a.atttypmod) AS atttypdefn, "
 							 "a.attlen, a.attalign, a.attisdropped, "
 							 "CASE WHEN a.attcollation <> at.typcollation "
@@ -11019,7 +11019,7 @@ dumpCompositeType(Archive *fout, const TypeInfo *tyinfo)
 							 "JOIN pg_catalog.pg_attribute a ON a.attrelid = ct.typrelid "
 							 "LEFT JOIN pg_catalog.pg_type at ON at.oid = a.atttypid "
 							 "WHERE ct.oid = $1 "
-							 "ORDER BY a.attnum");
+							 "ORDER BY a.attphysnum");
 
 		ExecuteSqlStatement(fout, query->data);
 
@@ -11214,7 +11214,7 @@ dumpCompositeTypeColComments(Archive *fout, const TypeInfo *tyinfo,
 	target = createPQExpBuffer();
 
 	ntups = PQntuples(res);
-	i_attnum = PQfnumber(res, "attnum");
+	i_attnum = PQfnumber(res, "attphysnum");
 	i_attname = PQfnumber(res, "attname");
 	i_attisdropped = PQfnumber(res, "attisdropped");
 	while (ncomments > 0)
@@ -14869,11 +14869,11 @@ dumpTable(Archive *fout, const TableInfo *tbinfo)
 									 "LEFT JOIN pg_catalog.pg_init_privs pip ON "
 									 "(at.attrelid = pip.objoid "
 									 "AND pip.classoid = 'pg_catalog.pg_class'::pg_catalog.regclass "
-									 "AND at.attnum = pip.objsubid) "
+									 "AND at.attphysnum = pip.objsubid) "
 									 "WHERE at.attrelid = $1 AND "
 									 "NOT at.attisdropped "
 									 "AND (at.attacl IS NOT NULL OR pip.initprivs IS NOT NULL) "
-									 "ORDER BY at.attnum");
+									 "ORDER BY at.attphysnum");
 			}
 			else
 			{
@@ -14883,7 +14883,7 @@ dumpTable(Archive *fout, const TableInfo *tbinfo)
 									 "FROM pg_catalog.pg_attribute "
 									 "WHERE attrelid = $1 AND NOT attisdropped "
 									 "AND attacl IS NOT NULL "
-									 "ORDER BY attnum");
+									 "ORDER BY attphysnum");
 			}
 
 			ExecuteSqlStatement(fout, query->data);
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index d1ae699171..a25ec298fd 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -1731,21 +1731,42 @@ describeOneTableDetails(const char *schemaname,
 			goto error_return;
 
 		/* Get the column that owns this sequence */
-		printfPQExpBuffer(&buf, "SELECT pg_catalog.quote_ident(nspname) || '.' ||"
-						  "\n   pg_catalog.quote_ident(relname) || '.' ||"
-						  "\n   pg_catalog.quote_ident(attname),"
-						  "\n   d.deptype"
-						  "\nFROM pg_catalog.pg_class c"
-						  "\nINNER JOIN pg_catalog.pg_depend d ON c.oid=d.refobjid"
-						  "\nINNER JOIN pg_catalog.pg_namespace n ON n.oid=c.relnamespace"
-						  "\nINNER JOIN pg_catalog.pg_attribute a ON ("
-						  "\n a.attrelid=c.oid AND"
-						  "\n a.attnum=d.refobjsubid)"
-						  "\nWHERE d.classid='pg_catalog.pg_class'::pg_catalog.regclass"
-						  "\n AND d.refclassid='pg_catalog.pg_class'::pg_catalog.regclass"
-						  "\n AND d.objid='%s'"
-						  "\n AND d.deptype IN ('a', 'i')",
-						  oid);
+		if (pset.sversion >= 150000) /* FIXME - bump me when pg15 branched */
+		{
+			printfPQExpBuffer(&buf, "SELECT pg_catalog.quote_ident(nspname) || '.' ||"
+							  "\n   pg_catalog.quote_ident(relname) || '.' ||"
+							  "\n   pg_catalog.quote_ident(attname),"
+							  "\n   d.deptype"
+							  "\nFROM pg_catalog.pg_class c"
+							  "\nINNER JOIN pg_catalog.pg_depend d ON c.oid=d.refobjid"
+							  "\nINNER JOIN pg_catalog.pg_namespace n ON n.oid=c.relnamespace"
+							  "\nINNER JOIN pg_catalog.pg_attribute a ON ("
+							  "\n a.attrelid=c.oid AND"
+							  "\n a.attphysnum=d.refobjsubid)"
+							  "\nWHERE d.classid='pg_catalog.pg_class'::pg_catalog.regclass"
+							  "\n AND d.refclassid='pg_catalog.pg_class'::pg_catalog.regclass"
+							  "\n AND d.objid='%s'"
+							  "\n AND d.deptype IN ('a', 'i')",
+							  oid);
+		}
+		else
+		{
+			printfPQExpBuffer(&buf, "SELECT pg_catalog.quote_ident(nspname) || '.' ||"
+							  "\n   pg_catalog.quote_ident(relname) || '.' ||"
+							  "\n   pg_catalog.quote_ident(attname),"
+							  "\n   d.deptype"
+							  "\nFROM pg_catalog.pg_class c"
+							  "\nINNER JOIN pg_catalog.pg_depend d ON c.oid=d.refobjid"
+							  "\nINNER JOIN pg_catalog.pg_namespace n ON n.oid=c.relnamespace"
+							  "\nINNER JOIN pg_catalog.pg_attribute a ON ("
+							  "\n a.attrelid=c.oid AND"
+							  "\n a.attnum=d.refobjsubid)"
+							  "\nWHERE d.classid='pg_catalog.pg_class'::pg_catalog.regclass"
+							  "\n AND d.refclassid='pg_catalog.pg_class'::pg_catalog.regclass"
+							  "\n AND d.objid='%s'"
+							  "\n AND d.deptype IN ('a', 'i')",
+							  oid);
+		}
 
 		result = PSQLexec(buf.data);
 
@@ -1819,11 +1840,23 @@ describeOneTableDetails(const char *schemaname,
 	if (show_column_details)
 	{
 		/* use "pretty" mode for expression to avoid excessive parentheses */
-		appendPQExpBufferStr(&buf,
-							 ",\n  (SELECT pg_catalog.pg_get_expr(d.adbin, d.adrelid, true)"
-							 "\n   FROM pg_catalog.pg_attrdef d"
-							 "\n   WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef)"
-							 ",\n  a.attnotnull");
+		if (pset.sversion >= 150000) /* FIXME - bump me when pg15 branched */
+		{
+			appendPQExpBufferStr(&buf,
+								 ",\n  (SELECT pg_catalog.pg_get_expr(d.adbin, d.adrelid, true)"
+								 "\n   FROM pg_catalog.pg_attrdef d"
+								 "\n   WHERE d.adrelid = a.attrelid AND d.adnum = a.attphysnum AND a.atthasdef)"
+								 ",\n  a.attnotnull");
+		}
+		else
+		{
+			appendPQExpBufferStr(&buf,
+								 ",\n  (SELECT pg_catalog.pg_get_expr(d.adbin, d.adrelid, true)"
+								 "\n   FROM pg_catalog.pg_attrdef d"
+								 "\n   WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef)"
+								 ",\n  a.attnotnull");
+		}
+
 		attrdef_col = cols++;
 		attnotnull_col = cols++;
 		appendPQExpBufferStr(&buf, ",\n  (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type t\n"
@@ -1843,7 +1876,15 @@ describeOneTableDetails(const char *schemaname,
 	if (tableinfo.relkind == RELKIND_INDEX ||
 		tableinfo.relkind == RELKIND_PARTITIONED_INDEX)
 	{
-		if (pset.sversion >= 110000)
+		if (pset.sversion >= 150000) /* FIXME - bump me when pg15 branched */
+		{
+			appendPQExpBuffer(&buf, ",\n  CASE WHEN a.attphysnum <= (SELECT i.indnkeyatts FROM pg_catalog.pg_index i WHERE i.indexrelid = '%s') THEN '%s' ELSE '%s' END AS is_key",
+							  oid,
+							  gettext_noop("yes"),
+							  gettext_noop("no"));
+			isindexkey_col = cols++;
+		}
+		else if (pset.sversion >= 110000)
 		{
 			appendPQExpBuffer(&buf, ",\n  CASE WHEN a.attnum <= (SELECT i.indnkeyatts FROM pg_catalog.pg_index i WHERE i.indexrelid = '%s') THEN '%s' ELSE '%s' END AS is_key",
 							  oid,
@@ -1851,7 +1892,11 @@ describeOneTableDetails(const char *schemaname,
 							  gettext_noop("no"));
 			isindexkey_col = cols++;
 		}
-		appendPQExpBufferStr(&buf, ",\n  pg_catalog.pg_get_indexdef(a.attrelid, a.attnum, TRUE) AS indexdef");
+
+		if (pset.sversion >= 150000) /* FIXME - bump me when pg15 branched */
+			appendPQExpBufferStr(&buf, ",\n  pg_catalog.pg_get_indexdef(a.attrelid, a.attphysnum, TRUE) AS indexdef");
+		else
+			appendPQExpBufferStr(&buf, ",\n  pg_catalog.pg_get_indexdef(a.attrelid, a.attnum, TRUE) AS indexdef");
 		indexdef_col = cols++;
 	}
 	/* FDW options for foreign table column */
@@ -1901,14 +1946,25 @@ describeOneTableDetails(const char *schemaname,
 			tableinfo.relkind == RELKIND_COMPOSITE_TYPE ||
 			tableinfo.relkind == RELKIND_PARTITIONED_TABLE)
 		{
-			appendPQExpBufferStr(&buf, ",\n  pg_catalog.col_description(a.attrelid, a.attnum)");
+			if (pset.sversion >= 150000) /* FIXME - bump me when pg15 branched */
+				appendPQExpBufferStr(&buf, ",\n  pg_catalog.col_description(a.attrelid, a.attphysnum)");
+			else
+				appendPQExpBufferStr(&buf, ",\n  pg_catalog.col_description(a.attrelid, a.attnum)");
 			attdescr_col = cols++;
 		}
 	}
 
 	appendPQExpBufferStr(&buf, "\nFROM pg_catalog.pg_attribute a");
-	appendPQExpBuffer(&buf, "\nWHERE a.attrelid = '%s' AND a.attnum > 0 AND NOT a.attisdropped", oid);
-	appendPQExpBufferStr(&buf, "\nORDER BY a.attnum;");
+	if (pset.sversion >= 150000) /* FIXME - bump me when pg15 branched */
+	{
+		appendPQExpBuffer(&buf, "\nWHERE a.attrelid = '%s' AND a.attphysnum > 0 AND NOT a.attisdropped", oid);
+		appendPQExpBufferStr(&buf, "\nORDER BY a.attphysnum;");
+	}
+	else
+	{
+		appendPQExpBuffer(&buf, "\nWHERE a.attrelid = '%s' AND a.attnum > 0 AND NOT a.attisdropped", oid);
+		appendPQExpBufferStr(&buf, "\nORDER BY a.attnum;");
+	}
 
 	res = PSQLexec(buf.data);
 	if (!res)
@@ -2930,7 +2986,39 @@ describeOneTableDetails(const char *schemaname,
 		/* print any publications */
 		if (pset.sversion >= 100000)
 		{
-			if (pset.sversion >= 150000)
+			if (pset.sversion >= 150000) /* FIXME - bump me when pg15 branched */
+			{
+				printfPQExpBuffer(&buf,
+								  "SELECT pubname\n"
+								  "     , NULL\n"
+								  "     , NULL\n"
+								  "FROM pg_catalog.pg_publication p\n"
+								  "     JOIN pg_catalog.pg_publication_namespace pn ON p.oid = pn.pnpubid\n"
+								  "     JOIN pg_catalog.pg_class pc ON pc.relnamespace = pn.pnnspid\n"
+								  "WHERE pc.oid ='%s' and pg_catalog.pg_relation_is_publishable('%s')\n"
+								  "UNION\n"
+								  "SELECT pubname\n"
+								  "     , pg_get_expr(pr.prqual, c.oid)\n"
+								  "     , (CASE WHEN pr.prattrs IS NOT NULL THEN\n"
+								  "         (SELECT string_agg(attname, ', ')\n"
+								  "           FROM pg_catalog.generate_series(0, pg_catalog.array_upper(pr.prattrs::pg_catalog.int2[], 1)) s,\n"
+								  "                pg_catalog.pg_attribute\n"
+								  "          WHERE attrelid = pr.prrelid AND attphysnum = prattrs[s])\n"
+								  "        ELSE NULL END) "
+								  "FROM pg_catalog.pg_publication p\n"
+								  "     JOIN pg_catalog.pg_publication_rel pr ON p.oid = pr.prpubid\n"
+								  "     JOIN pg_catalog.pg_class c ON c.oid = pr.prrelid\n"
+								  "WHERE pr.prrelid = '%s'\n"
+								  "UNION\n"
+								  "SELECT pubname\n"
+								  "     , NULL\n"
+								  "     , NULL\n"
+								  "FROM pg_catalog.pg_publication p\n"
+								  "WHERE p.puballtables AND pg_catalog.pg_relation_is_publishable('%s')\n"
+								  "ORDER BY 1;",
+								  oid, oid, oid, oid);
+			}
+			else if (pset.sversion >= 150000)
 			{
 				printfPQExpBuffer(&buf,
 								  "SELECT pubname\n"
@@ -4609,7 +4697,7 @@ listExtendedStats(const char *pattern)
 						  "   FROM pg_catalog.unnest(es.stxkeys) s(attnum) \n"
 						  "   JOIN pg_catalog.pg_attribute a \n"
 						  "   ON (es.stxrelid = a.attrelid \n"
-						  "   AND a.attnum = s.attnum \n"
+						  "   AND a.attnum = s.attsnum \n"
 						  "   AND NOT a.attisdropped)), \n"
 						  "es.stxrelid::pg_catalog.regclass) AS \"%s\"",
 						  gettext_noop("Definition"));
@@ -6279,7 +6367,21 @@ describePublications(const char *pattern)
 			/* Get the tables for the specified publication */
 			printfPQExpBuffer(&buf,
 							  "SELECT n.nspname, c.relname");
-			if (pset.sversion >= 150000)
+			if (pset.sversion >= 150000) /* FIXME - bump me when pg15 branched */
+			{
+				appendPQExpBufferStr(&buf,
+									 ", pg_get_expr(pr.prqual, c.oid)");
+				appendPQExpBufferStr(&buf,
+									 ", (CASE WHEN pr.prattrs IS NOT NULL THEN\n"
+									 "     pg_catalog.array_to_string("
+									 "      ARRAY(SELECT attname\n"
+									 "              FROM\n"
+									 "                pg_catalog.generate_series(0, pg_catalog.array_upper(pr.prattrs::pg_catalog.int2[], 1)) s,\n"
+									 "                pg_catalog.pg_attribute\n"
+									 "        WHERE attrelid = c.oid AND attphysnum = prattrs[s]), ', ')\n"
+									 "       ELSE NULL END)");
+			}
+			else if (pset.sversion >= 150000)
 			{
 				appendPQExpBufferStr(&buf,
 									 ", pg_get_expr(pr.prqual, c.oid)");
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index bd44a1d55d..df5df475b8 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -516,7 +516,7 @@ static const SchemaQuery Query_for_list_of_arguments = {
 
 static const SchemaQuery Query_for_list_of_attributes = {
 	.catname = "pg_catalog.pg_attribute a, pg_catalog.pg_class c",
-	.selcondition = "c.oid = a.attrelid and a.attnum > 0 and not a.attisdropped",
+	.selcondition = "c.oid = a.attrelid and a.attphysnum > 0 and not a.attisdropped",
 	.result = "a.attname",
 	.refname = "c.relname",
 	.refviscondition = "pg_catalog.pg_table_is_visible(c.oid)",
@@ -525,7 +525,7 @@ static const SchemaQuery Query_for_list_of_attributes = {
 
 static const SchemaQuery Query_for_list_of_attribute_numbers = {
 	.catname = "pg_catalog.pg_attribute a, pg_catalog.pg_class c",
-	.selcondition = "c.oid = a.attrelid and a.attnum > 0 and not a.attisdropped",
+	.selcondition = "c.oid = a.attrelid and a.attphysnum > 0 and not a.attisdropped",
 	.result = "a.attnum::pg_catalog.text",
 	.refname = "c.relname",
 	.refviscondition = "pg_catalog.pg_table_is_visible(c.oid)",
diff --git a/src/include/access/genam.h b/src/include/access/genam.h
index 134b20f1e6..4d95e2801a 100644
--- a/src/include/access/genam.h
+++ b/src/include/access/genam.h
@@ -183,15 +183,15 @@ extern IndexBulkDeleteResult *index_bulk_delete(IndexVacuumInfo *info,
 extern IndexBulkDeleteResult *index_vacuum_cleanup(IndexVacuumInfo *info,
 												   IndexBulkDeleteResult *istat);
 extern bool index_can_return(Relation indexRelation, int attno);
-extern RegProcedure index_getprocid(Relation irel, AttrNumber attnum,
+extern RegProcedure index_getprocid(Relation irel, AttrNumber attphysnum,
 									uint16 procnum);
-extern FmgrInfo *index_getprocinfo(Relation irel, AttrNumber attnum,
+extern FmgrInfo *index_getprocinfo(Relation irel, AttrNumber attphysnum,
 								   uint16 procnum);
 extern void index_store_float8_orderby_distances(IndexScanDesc scan,
 												 Oid *orderByTypes,
 												 IndexOrderByDistance *distances,
 												 bool recheckOrderBy);
-extern bytea *index_opclass_options(Relation relation, AttrNumber attnum,
+extern bytea *index_opclass_options(Relation relation, AttrNumber attphysnum,
 									Datum attoptions, bool validate);
 
 
diff --git a/src/include/access/gin_private.h b/src/include/access/gin_private.h
index 2935d2f353..733686d724 100644
--- a/src/include/access/gin_private.h
+++ b/src/include/access/gin_private.h
@@ -95,13 +95,13 @@ extern Buffer GinNewBuffer(Relation index);
 extern void GinInitBuffer(Buffer b, uint32 f);
 extern void GinInitPage(Page page, uint32 f, Size pageSize);
 extern void GinInitMetabuffer(Buffer b);
-extern int	ginCompareEntries(GinState *ginstate, OffsetNumber attnum,
+extern int	ginCompareEntries(GinState *ginstate, OffsetNumber attphysnum,
 							  Datum a, GinNullCategory categorya,
 							  Datum b, GinNullCategory categoryb);
 extern int	ginCompareAttEntries(GinState *ginstate,
 								 OffsetNumber attnuma, Datum a, GinNullCategory categorya,
 								 OffsetNumber attnumb, Datum b, GinNullCategory categoryb);
-extern Datum *ginExtractEntries(GinState *ginstate, OffsetNumber attnum,
+extern Datum *ginExtractEntries(GinState *ginstate, OffsetNumber attphysnum,
 								Datum value, bool isNull,
 								int32 *nentries, GinNullCategory **categories);
 
@@ -119,7 +119,7 @@ extern bool gininsert(Relation index, Datum *values, bool *isnull,
 					  bool indexUnchanged,
 					  struct IndexInfo *indexInfo);
 extern void ginEntryInsert(GinState *ginstate,
-						   OffsetNumber attnum, Datum key, GinNullCategory category,
+						   OffsetNumber attphysnum, Datum key, GinNullCategory category,
 						   ItemPointerData *items, uint32 nitem,
 						   GinStatsData *buildStats);
 
@@ -210,13 +210,13 @@ extern void ginInsertValue(GinBtree btree, GinBtreeStack *stack,
 
 /* ginentrypage.c */
 extern IndexTuple GinFormTuple(GinState *ginstate,
-							   OffsetNumber attnum, Datum key, GinNullCategory category,
+							   OffsetNumber attphysnum, Datum key, GinNullCategory category,
 							   Pointer data, Size dataSize, int nipd, bool errorTooBig);
-extern void ginPrepareEntryScan(GinBtree btree, OffsetNumber attnum,
+extern void ginPrepareEntryScan(GinBtree btree, OffsetNumber attphysnum,
 								Datum key, GinNullCategory category,
 								GinState *ginstate);
 extern void ginEntryFillRoot(GinBtree btree, Page root, BlockNumber lblkno, Page lpage, BlockNumber rblkno, Page rpage);
-extern ItemPointer ginReadTuple(GinState *ginstate, OffsetNumber attnum,
+extern ItemPointer ginReadTuple(GinState *ginstate, OffsetNumber attphysnum,
 								IndexTuple itup, int *nitems);
 
 /* gindatapage.c */
@@ -302,7 +302,7 @@ typedef struct GinScanKeyData
 	Pointer    *extra_data;
 	StrategyNumber strategy;
 	int32		searchMode;
-	OffsetNumber attnum;
+	OffsetNumber attphysnum;
 
 	/*
 	 * An excludeOnly scan key is not able to enumerate all matching tuples.
@@ -340,7 +340,7 @@ typedef struct GinScanEntryData
 	Pointer		extra_data;
 	StrategyNumber strategy;
 	int32		searchMode;
-	OffsetNumber attnum;
+	OffsetNumber attphysnum;
 
 	/* Current page in posting tree */
 	Buffer		buffer;
@@ -419,7 +419,7 @@ typedef struct GinEntryAccumulator
 	RBTNode		rbtnode;
 	Datum		key;
 	GinNullCategory category;
-	OffsetNumber attnum;
+	OffsetNumber attphysnum;
 	bool		shouldSort;
 	ItemPointerData *list;
 	uint32		maxcount;		/* allocated size of list[] */
@@ -438,12 +438,12 @@ typedef struct
 
 extern void ginInitBA(BuildAccumulator *accum);
 extern void ginInsertBAEntries(BuildAccumulator *accum,
-							   ItemPointer heapptr, OffsetNumber attnum,
+							   ItemPointer heapptr, OffsetNumber attphysnum,
 							   Datum *entries, GinNullCategory *categories,
 							   int32 nentries);
 extern void ginBeginBAScan(BuildAccumulator *accum);
 extern ItemPointerData *ginGetBAEntry(BuildAccumulator *accum,
-									  OffsetNumber *attnum, Datum *key, GinNullCategory *category,
+									  OffsetNumber *attphysnum, Datum *key, GinNullCategory *category,
 									  uint32 *n);
 
 /* ginfast.c */
@@ -460,7 +460,7 @@ extern void ginHeapTupleFastInsert(GinState *ginstate,
 								   GinTupleCollector *collector);
 extern void ginHeapTupleFastCollect(GinState *ginstate,
 									GinTupleCollector *collector,
-									OffsetNumber attnum, Datum value, bool isNull,
+									OffsetNumber attphysnum, Datum value, bool isNull,
 									ItemPointer ht_ctid);
 extern void ginInsertCleanup(GinState *ginstate, bool full_clean,
 							 bool fill_fsm, bool forceCleanup, IndexBulkDeleteResult *stats);
diff --git a/src/include/access/htup_details.h b/src/include/access/htup_details.h
index 51a60eda08..a04c5df02e 100644
--- a/src/include/access/htup_details.h
+++ b/src/include/access/htup_details.h
@@ -697,13 +697,13 @@ extern void heap_fill_tuple(TupleDesc tupleDesc,
 							Datum *values, bool *isnull,
 							char *data, Size data_size,
 							uint16 *infomask, bits8 *bit);
-extern bool heap_attisnull(HeapTuple tup, int attnum, TupleDesc tupleDesc);
-extern Datum nocachegetattr(HeapTuple tup, int attnum,
+extern bool heap_attisnull(HeapTuple tup, int attphysnum, TupleDesc tupleDesc);
+extern Datum nocachegetattr(HeapTuple tup, int attphysnum,
 							TupleDesc att);
-extern Datum heap_getsysattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
+extern Datum heap_getsysattr(HeapTuple tup, int attphysnum, TupleDesc tupleDesc,
 							 bool *isnull);
 extern Datum getmissingattr(TupleDesc tupleDesc,
-							int attnum, bool *isnull);
+							int attphysnum, bool *isnull);
 extern HeapTuple heap_copytuple(HeapTuple tuple);
 extern void heap_copytuple_with_tuple(HeapTuple src, HeapTuple dest);
 extern Datum heap_copy_tuple_as_datum(HeapTuple tuple, TupleDesc tupleDesc);
@@ -740,45 +740,45 @@ extern MinimalTuple minimal_expand_tuple(HeapTuple sourceTuple, TupleDesc tupleD
  *		value, or a pointer into the data area of the tuple).
  *
  *		This must not be used when a system attribute might be requested.
- *		Furthermore, the passed attnum MUST be valid.  Use heap_getattr()
+ *		Furthermore, the passed attphysnum MUST be valid.  Use heap_getattr()
  *		instead, if in doubt.
  *
  *		This gets called many times, so we macro the cacheable and NULL
  *		lookups, and call nocachegetattr() for the rest.
  */
 static inline Datum
-fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
+fastgetattr(HeapTuple tup, int attphysnum, TupleDesc tupleDesc, bool *isnull)
 {
-	Assert(attnum > 0);
+	Assert(attphysnum > 0);
 
 	*isnull = false;
 	if (HeapTupleNoNulls(tup))
 	{
 		Form_pg_attribute att;
 
-		att = TupleDescAttr(tupleDesc, attnum - 1);
+		att = TupleDescAttr(tupleDesc, attphysnum - 1);
 		if (att->attcacheoff >= 0)
 			return fetchatt(att, (char *) tup->t_data + tup->t_data->t_hoff +
 							att->attcacheoff);
 		else
-			return nocachegetattr(tup, attnum, tupleDesc);
+			return nocachegetattr(tup, attphysnum, tupleDesc);
 	}
 	else
 	{
-		if (att_isnull(attnum - 1, tup->t_data->t_bits))
+		if (att_isnull(attphysnum - 1, tup->t_data->t_bits))
 		{
 			*isnull = true;
 			return (Datum) NULL;
 		}
 		else
-			return nocachegetattr(tup, attnum, tupleDesc);
+			return nocachegetattr(tup, attphysnum, tupleDesc);
 	}
 }
 
 /*
  *	heap_getattr
  *		Extract an attribute of a heap tuple and return it as a Datum.
- *		This works for either system or user attributes.  The given attnum
+ *		This works for either system or user attributes.  The given attphysnum
  *		is properly range-checked.
  *
  *		If the field in question has a NULL value, we return a zero Datum
@@ -790,17 +790,17 @@ fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
  *
  */
 static inline Datum
-heap_getattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
+heap_getattr(HeapTuple tup, int attphysnum, TupleDesc tupleDesc, bool *isnull)
 {
-	if (attnum > 0)
+	if (attphysnum > 0)
 	{
-		if (attnum > (int) HeapTupleHeaderGetNatts(tup->t_data))
-			return getmissingattr(tupleDesc, attnum, isnull);
+		if (attphysnum > (int) HeapTupleHeaderGetNatts(tup->t_data))
+			return getmissingattr(tupleDesc, attphysnum, isnull);
 		else
-			return fastgetattr(tup, attnum, tupleDesc, isnull);
+			return fastgetattr(tup, attphysnum, tupleDesc, isnull);
 	}
 	else
-		return heap_getsysattr(tup, attnum, tupleDesc, isnull);
+		return heap_getsysattr(tup, attphysnum, tupleDesc, isnull);
 }
 #endif							/* FRONTEND */
 
diff --git a/src/include/access/itup.h b/src/include/access/itup.h
index 2c8877e991..c31a20d53f 100644
--- a/src/include/access/itup.h
+++ b/src/include/access/itup.h
@@ -97,31 +97,31 @@ typedef IndexAttributeBitMapData * IndexAttributeBitMap;
  *
  * ----------------
  */
-#define index_getattr(tup, attnum, tupleDesc, isnull) \
+#define index_getattr(tup, attphysnum, tupleDesc, isnull) \
 ( \
-	AssertMacro(PointerIsValid(isnull) && (attnum) > 0), \
+	AssertMacro(PointerIsValid(isnull) && (attphysnum) > 0), \
 	*(isnull) = false, \
 	!IndexTupleHasNulls(tup) ? \
 	( \
-		TupleDescAttr((tupleDesc), (attnum)-1)->attcacheoff >= 0 ? \
+		TupleDescAttr((tupleDesc), (attphysnum)-1)->attcacheoff >= 0 ? \
 		( \
-			fetchatt(TupleDescAttr((tupleDesc), (attnum)-1), \
+			fetchatt(TupleDescAttr((tupleDesc), (attphysnum)-1), \
 			(char *) (tup) + IndexInfoFindDataOffset((tup)->t_info) \
-			+ TupleDescAttr((tupleDesc), (attnum)-1)->attcacheoff) \
+			+ TupleDescAttr((tupleDesc), (attphysnum)-1)->attcacheoff) \
 		) \
 		: \
-			nocache_index_getattr((tup), (attnum), (tupleDesc)) \
+			nocache_index_getattr((tup), (attphysnum), (tupleDesc)) \
 	) \
 	: \
 	( \
-		(att_isnull((attnum)-1, (char *)(tup) + sizeof(IndexTupleData))) ? \
+		(att_isnull((attphysnum)-1, (char *)(tup) + sizeof(IndexTupleData))) ? \
 		( \
 			*(isnull) = true, \
 			(Datum)NULL \
 		) \
 		: \
 		( \
-			nocache_index_getattr((tup), (attnum), (tupleDesc)) \
+			nocache_index_getattr((tup), (attphysnum), (tupleDesc)) \
 		) \
 	) \
 )
@@ -150,7 +150,7 @@ typedef IndexAttributeBitMapData * IndexAttributeBitMap;
 /* routines in indextuple.c */
 extern IndexTuple index_form_tuple(TupleDesc tupleDescriptor,
 								   Datum *values, bool *isnull);
-extern Datum nocache_index_getattr(IndexTuple tup, int attnum,
+extern Datum nocache_index_getattr(IndexTuple tup, int attphysnum,
 								   TupleDesc tupleDesc);
 extern void index_deform_tuple(IndexTuple tup, TupleDesc tupleDescriptor,
 							   Datum *values, bool *isnull);
diff --git a/src/include/bootstrap/bootstrap.h b/src/include/bootstrap/bootstrap.h
index 49d4ad560f..cd4c2590f3 100644
--- a/src/include/bootstrap/bootstrap.h
+++ b/src/include/bootstrap/bootstrap.h
@@ -37,7 +37,7 @@ extern void BootstrapModeMain(int argc, char *argv[], bool check_only) pg_attrib
 extern void closerel(char *name);
 extern void boot_openrel(char *name);
 
-extern void DefineAttr(char *name, char *type, int attnum, int nullness);
+extern void DefineAttr(char *name, char *type, int attphysnum, int nullness);
 extern void InsertOneTuple(void);
 extern void InsertOneValue(char *value, int i);
 extern void InsertOneNull(int i);
diff --git a/src/include/catalog/dependency.h b/src/include/catalog/dependency.h
index d027075a4c..076fe7ff28 100644
--- a/src/include/catalog/dependency.h
+++ b/src/include/catalog/dependency.h
@@ -220,7 +220,7 @@ extern List *getAutoExtensionsOfObject(Oid classId, Oid objectId);
 
 extern bool sequenceIsOwned(Oid seqId, char deptype, Oid *tableId, int32 *colId);
 extern List *getOwnedSequences(Oid relid);
-extern Oid	getIdentitySequence(Oid relid, AttrNumber attnum, bool missing_ok);
+extern Oid	getIdentitySequence(Oid relid, AttrNumber attphysnum, bool missing_ok);
 
 extern Oid	get_index_constraint(Oid indexId);
 
diff --git a/src/include/catalog/heap.h b/src/include/catalog/heap.h
index 07c5b88f0e..69d226dfd6 100644
--- a/src/include/catalog/heap.h
+++ b/src/include/catalog/heap.h
@@ -26,7 +26,7 @@
 
 typedef struct RawColumnDefault
 {
-	AttrNumber	attnum;			/* attribute to attach default to */
+	AttrNumber	attphysnum;			/* attribute to attach default to */
 	Node	   *raw_default;	/* default value (untransformed parse tree) */
 	bool		missingMode;	/* true if part of add column processing */
 	char		generated;		/* attgenerated setting */
@@ -37,7 +37,7 @@ typedef struct CookedConstraint
 	ConstrType	contype;		/* CONSTR_DEFAULT or CONSTR_CHECK */
 	Oid			conoid;			/* constr OID if created, otherwise Invalid */
 	char	   *name;			/* name, or NULL if none */
-	AttrNumber	attnum;			/* which attr (only for DEFAULT) */
+	AttrNumber	attphysnum;			/* which attr (only for DEFAULT) */
 	Node	   *expr;			/* transformed default or check expr */
 	bool		skip_validation;	/* skip validation? (only for CHECK) */
 	bool		is_local;		/* constraint has local (non-inherited) def */
@@ -127,10 +127,10 @@ extern Node *cookDefault(ParseState *pstate,
 extern void DeleteRelationTuple(Oid relid);
 extern void DeleteAttributeTuples(Oid relid);
 extern void DeleteSystemAttributeTuples(Oid relid);
-extern void RemoveAttributeById(Oid relid, AttrNumber attnum);
+extern void RemoveAttributeById(Oid relid, AttrNumber attphysnum);
 
 extern void CopyStatistics(Oid fromrelid, Oid torelid);
-extern void RemoveStatistics(Oid relid, AttrNumber attnum);
+extern void RemoveStatistics(Oid relid, AttrNumber attphysnum);
 
 extern const FormData_pg_attribute *SystemAttributeDefinition(AttrNumber attno);
 
diff --git a/src/include/catalog/pg_attrdef.h b/src/include/catalog/pg_attrdef.h
index a21dd3812b..53373c4d63 100644
--- a/src/include/catalog/pg_attrdef.h
+++ b/src/include/catalog/pg_attrdef.h
@@ -33,7 +33,7 @@ CATALOG(pg_attrdef,2604,AttrDefaultRelationId)
 
 	Oid			adrelid BKI_LOOKUP(pg_class);	/* OID of table containing
 												 * attribute */
-	int16		adnum;			/* attnum of attribute */
+	int16		adnum;			/* attphysnum of attribute */
 
 #ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	pg_node_tree adbin BKI_FORCE_NOT_NULL;	/* nodeToString representation of
@@ -53,18 +53,18 @@ DECLARE_TOAST(pg_attrdef, 2830, 2831);
 DECLARE_UNIQUE_INDEX(pg_attrdef_adrelid_adnum_index, 2656, AttrDefaultIndexId, on pg_attrdef using btree(adrelid oid_ops, adnum int2_ops));
 DECLARE_UNIQUE_INDEX_PKEY(pg_attrdef_oid_index, 2657, AttrDefaultOidIndexId, on pg_attrdef using btree(oid oid_ops));
 
-DECLARE_FOREIGN_KEY((adrelid, adnum), pg_attribute, (attrelid, attnum));
+DECLARE_FOREIGN_KEY((adrelid, adnum), pg_attribute, (attrelid, attphysnum));
 
 
-extern Oid	StoreAttrDefault(Relation rel, AttrNumber attnum,
+extern Oid	StoreAttrDefault(Relation rel, AttrNumber attphysnum,
 							 Node *expr, bool is_internal,
 							 bool add_column_mode);
-extern void RemoveAttrDefault(Oid relid, AttrNumber attnum,
+extern void RemoveAttrDefault(Oid relid, AttrNumber attphysnum,
 							  DropBehavior behavior,
 							  bool complain, bool internal);
 extern void RemoveAttrDefaultById(Oid attrdefId);
 
-extern Oid	GetAttrDefaultOid(Oid relid, AttrNumber attnum);
+extern Oid	GetAttrDefaultOid(Oid relid, AttrNumber attphysnum);
 extern ObjectAddress GetAttrDefaultColumnAddress(Oid attrdefoid);
 
 #endif							/* PG_ATTRDEF_H */
diff --git a/src/include/catalog/pg_attribute.h b/src/include/catalog/pg_attribute.h
index 053294c99f..746566eb8d 100644
--- a/src/include/catalog/pg_attribute.h
+++ b/src/include/catalog/pg_attribute.h
@@ -68,7 +68,7 @@ CATALOG(pg_attribute,1249,AttributeRelationId) BKI_BOOTSTRAP BKI_ROWTYPE_OID(75,
 	int16		attlen;
 
 	/*
-	 * attnum is the "attribute number" for the attribute:	A value that
+	 * attphysnum is the "attribute number" for the attribute:	A value that
 	 * uniquely identifies this attribute within its class. For user
 	 * attributes, Attribute numbers are greater than 0 and not greater than
 	 * the number of attributes in the class. I.e. if the Class pg_class says
@@ -78,9 +78,9 @@ CATALOG(pg_attribute,1249,AttributeRelationId) BKI_BOOTSTRAP BKI_ROWTYPE_OID(75,
 	 * System attributes have attribute numbers less than 0 that are unique
 	 * within the class, but not constrained to any particular range.
 	 *
-	 * Note that (attnum - 1) is often used as the index to an array.
+	 * Note that (attphysnum - 1) is often used as the index to an array.
 	 */
-	int16		attnum;
+	int16		attphysnum;
 
 	/*
 	 * attndims is the declared number of dimensions, if an array type,
@@ -207,7 +207,7 @@ CATALOG(pg_attribute,1249,AttributeRelationId) BKI_BOOTSTRAP BKI_ROWTYPE_OID(75,
 typedef FormData_pg_attribute *Form_pg_attribute;
 
 DECLARE_UNIQUE_INDEX(pg_attribute_relid_attnam_index, 2658, AttributeRelidNameIndexId, on pg_attribute using btree(attrelid oid_ops, attname name_ops));
-DECLARE_UNIQUE_INDEX_PKEY(pg_attribute_relid_attnum_index, 2659, AttributeRelidNumIndexId, on pg_attribute using btree(attrelid oid_ops, attnum int2_ops));
+DECLARE_UNIQUE_INDEX_PKEY(pg_attribute_relid_attphysnum_index, 2659, AttributeRelidPhysNumIndexId, on pg_attribute using btree(attrelid oid_ops, attphysnum int2_ops));
 
 #ifdef EXPOSE_TO_CLIENT_CODE
 
diff --git a/src/include/catalog/pg_constraint.h b/src/include/catalog/pg_constraint.h
index e7d967f137..39c5c23095 100644
--- a/src/include/catalog/pg_constraint.h
+++ b/src/include/catalog/pg_constraint.h
@@ -173,8 +173,8 @@ DECLARE_UNIQUE_INDEX_PKEY(pg_constraint_oid_index, 2667, ConstraintOidIndexId, o
 DECLARE_INDEX(pg_constraint_conparentid_index, 2579, ConstraintParentIndexId, on pg_constraint using btree(conparentid oid_ops));
 
 /* conkey can contain zero (InvalidAttrNumber) if a whole-row Var is used */
-DECLARE_ARRAY_FOREIGN_KEY_OPT((conrelid, conkey), pg_attribute, (attrelid, attnum));
-DECLARE_ARRAY_FOREIGN_KEY((confrelid, confkey), pg_attribute, (attrelid, attnum));
+DECLARE_ARRAY_FOREIGN_KEY_OPT((conrelid, conkey), pg_attribute, (attrelid, attphysnum));
+DECLARE_ARRAY_FOREIGN_KEY((confrelid, confkey), pg_attribute, (attrelid, attphysnum));
 
 #ifdef EXPOSE_TO_CLIENT_CODE
 
diff --git a/src/include/catalog/pg_index.h b/src/include/catalog/pg_index.h
index f853846ee1..13d4fcb805 100644
--- a/src/include/catalog/pg_index.h
+++ b/src/include/catalog/pg_index.h
@@ -73,7 +73,7 @@ DECLARE_INDEX(pg_index_indrelid_index, 2678, IndexIndrelidIndexId, on pg_index u
 DECLARE_UNIQUE_INDEX_PKEY(pg_index_indexrelid_index, 2679, IndexRelidIndexId, on pg_index using btree(indexrelid oid_ops));
 
 /* indkey can contain zero (InvalidAttrNumber) to represent expressions */
-DECLARE_ARRAY_FOREIGN_KEY_OPT((indrelid, indkey), pg_attribute, (attrelid, attnum));
+DECLARE_ARRAY_FOREIGN_KEY_OPT((indrelid, indkey), pg_attribute, (attrelid, attphysnum));
 
 #ifdef EXPOSE_TO_CLIENT_CODE
 
diff --git a/src/include/catalog/pg_partitioned_table.h b/src/include/catalog/pg_partitioned_table.h
index 9b78f84cd5..c6da704bf4 100644
--- a/src/include/catalog/pg_partitioned_table.h
+++ b/src/include/catalog/pg_partitioned_table.h
@@ -69,6 +69,6 @@ DECLARE_TOAST(pg_partitioned_table, 4165, 4166);
 DECLARE_UNIQUE_INDEX_PKEY(pg_partitioned_table_partrelid_index, 3351, PartitionedRelidIndexId, on pg_partitioned_table using btree(partrelid oid_ops));
 
 /* partattrs can contain zero (InvalidAttrNumber) to represent expressions */
-DECLARE_ARRAY_FOREIGN_KEY_OPT((partrelid, partattrs), pg_attribute, (attrelid, attnum));
+DECLARE_ARRAY_FOREIGN_KEY_OPT((partrelid, partattrs), pg_attribute, (attrelid, attphysnum));
 
 #endif							/* PG_PARTITIONED_TABLE_H */
diff --git a/src/include/catalog/pg_statistic.h b/src/include/catalog/pg_statistic.h
index cdf7448139..d63b8dd30f 100644
--- a/src/include/catalog/pg_statistic.h
+++ b/src/include/catalog/pg_statistic.h
@@ -138,7 +138,7 @@ DECLARE_TOAST(pg_statistic, 2840, 2841);
 
 DECLARE_UNIQUE_INDEX_PKEY(pg_statistic_relid_att_inh_index, 2696, StatisticRelidAttnumInhIndexId, on pg_statistic using btree(starelid oid_ops, staattnum int2_ops, stainherit bool_ops));
 
-DECLARE_FOREIGN_KEY((starelid, staattnum), pg_attribute, (attrelid, attnum));
+DECLARE_FOREIGN_KEY((starelid, staattnum), pg_attribute, (attrelid, attphysnum));
 
 #ifdef EXPOSE_TO_CLIENT_CODE
 
diff --git a/src/include/catalog/pg_statistic_ext.h b/src/include/catalog/pg_statistic_ext.h
index b8520ba923..96b260e34d 100644
--- a/src/include/catalog/pg_statistic_ext.h
+++ b/src/include/catalog/pg_statistic_ext.h
@@ -74,7 +74,7 @@ DECLARE_UNIQUE_INDEX_PKEY(pg_statistic_ext_oid_index, 3380, StatisticExtOidIndex
 DECLARE_UNIQUE_INDEX(pg_statistic_ext_name_index, 3997, StatisticExtNameIndexId, on pg_statistic_ext using btree(stxname name_ops, stxnamespace oid_ops));
 DECLARE_INDEX(pg_statistic_ext_relid_index, 3379, StatisticExtRelidIndexId, on pg_statistic_ext using btree(stxrelid oid_ops));
 
-DECLARE_ARRAY_FOREIGN_KEY((stxrelid, stxkeys), pg_attribute, (attrelid, attnum));
+DECLARE_ARRAY_FOREIGN_KEY((stxrelid, stxkeys), pg_attribute, (attrelid, attphysnum));
 
 #ifdef EXPOSE_TO_CLIENT_CODE
 
diff --git a/src/include/catalog/pg_trigger.h b/src/include/catalog/pg_trigger.h
index 194277bca5..7036916879 100644
--- a/src/include/catalog/pg_trigger.h
+++ b/src/include/catalog/pg_trigger.h
@@ -85,7 +85,7 @@ DECLARE_INDEX(pg_trigger_tgconstraint_index, 2699, TriggerConstraintIndexId, on
 DECLARE_UNIQUE_INDEX(pg_trigger_tgrelid_tgname_index, 2701, TriggerRelidNameIndexId, on pg_trigger using btree(tgrelid oid_ops, tgname name_ops));
 DECLARE_UNIQUE_INDEX_PKEY(pg_trigger_oid_index, 2702, TriggerOidIndexId, on pg_trigger using btree(oid oid_ops));
 
-DECLARE_ARRAY_FOREIGN_KEY((tgrelid, tgattr), pg_attribute, (attrelid, attnum));
+DECLARE_ARRAY_FOREIGN_KEY((tgrelid, tgattr), pg_attribute, (attrelid, attphysnum));
 
 #ifdef EXPOSE_TO_CLIENT_CODE
 
diff --git a/src/include/executor/execExpr.h b/src/include/executor/execExpr.h
index e34db8c93c..709b84bd79 100644
--- a/src/include/executor/execExpr.h
+++ b/src/include/executor/execExpr.h
@@ -301,9 +301,9 @@ typedef struct ExprEvalStep
 		/* for EEOP_INNER/OUTER/SCAN_[SYS]VAR[_FIRST] */
 		struct
 		{
-			/* attnum is attr number - 1 for regular VAR ... */
+			/* attphysnum is attr number - 1 for regular VAR ... */
 			/* but it's just the normal (negative) attr number for SYSVAR */
-			int			attnum;
+			int			attphysnum;
 			Oid			vartype;	/* type OID of variable */
 		}			var;
 
@@ -323,7 +323,7 @@ typedef struct ExprEvalStep
 			/* target index in ExprState->resultslot->tts_values/nulls */
 			int			resultnum;
 			/* source attribute number - 1 */
-			int			attnum;
+			int			attphysnum;
 		}			assign_var;
 
 		/* for EEOP_ASSIGN_TMP[_MAKE_RO] */
diff --git a/src/include/executor/spi.h b/src/include/executor/spi.h
index b2c0c7486c..a49ea6cfef 100644
--- a/src/include/executor/spi.h
+++ b/src/include/executor/spi.h
@@ -161,7 +161,7 @@ extern CachedPlan *SPI_plan_get_cached_plan(SPIPlanPtr plan);
 extern HeapTuple SPI_copytuple(HeapTuple tuple);
 extern HeapTupleHeader SPI_returntuple(HeapTuple tuple, TupleDesc tupdesc);
 extern HeapTuple SPI_modifytuple(Relation rel, HeapTuple tuple, int natts,
-								 int *attnum, Datum *Values, const char *Nulls);
+								 int *attphysnum, Datum *Values, const char *Nulls);
 extern int	SPI_fnumber(TupleDesc tupdesc, const char *fname);
 extern char *SPI_fname(TupleDesc tupdesc, int fnumber);
 extern char *SPI_getvalue(HeapTuple tuple, TupleDesc tupdesc, int fnumber);
diff --git a/src/include/executor/tuptable.h b/src/include/executor/tuptable.h
index 6306bb6fc6..3b8f0607a0 100644
--- a/src/include/executor/tuptable.h
+++ b/src/include/executor/tuptable.h
@@ -165,7 +165,7 @@ struct TupleTableSlotOps
 	 * to false, if it's not NULL. Throws an error if the slot type does not
 	 * support system attributes.
 	 */
-	Datum		(*getsysattr) (TupleTableSlot *slot, int attnum, bool *isnull);
+	Datum		(*getsysattr) (TupleTableSlot *slot, int attphysnum, bool *isnull);
 
 	/*
 	 * Make the contents of the slot solely depend on the slot, and not on
@@ -328,7 +328,7 @@ extern MinimalTuple ExecFetchSlotMinimalTuple(TupleTableSlot *slot,
 extern Datum ExecFetchSlotHeapTupleDatum(TupleTableSlot *slot);
 extern void slot_getmissingattrs(TupleTableSlot *slot, int startAttNum,
 								 int lastAttNum);
-extern void slot_getsomeattrs_int(TupleTableSlot *slot, int attnum);
+extern void slot_getsomeattrs_int(TupleTableSlot *slot, int attphysnum);
 
 
 #ifndef FRONTEND
@@ -338,10 +338,10 @@ extern void slot_getsomeattrs_int(TupleTableSlot *slot, int attnum);
  * valid at least up through the attnum'th entry.
  */
 static inline void
-slot_getsomeattrs(TupleTableSlot *slot, int attnum)
+slot_getsomeattrs(TupleTableSlot *slot, int attphysnum)
 {
-	if (slot->tts_nvalid < attnum)
-		slot_getsomeattrs_int(slot, attnum);
+	if (slot->tts_nvalid < attphysnum)
+		slot_getsomeattrs_int(slot, attphysnum);
 }
 
 /*
@@ -364,31 +364,31 @@ slot_getallattrs(TupleTableSlot *slot)
  * it.
  */
 static inline bool
-slot_attisnull(TupleTableSlot *slot, int attnum)
+slot_attisnull(TupleTableSlot *slot, int attphysnum)
 {
-	AssertArg(attnum > 0);
+	AssertArg(attphysnum > 0);
 
-	if (attnum > slot->tts_nvalid)
-		slot_getsomeattrs(slot, attnum);
+	if (attphysnum > slot->tts_nvalid)
+		slot_getsomeattrs(slot, attphysnum);
 
-	return slot->tts_isnull[attnum - 1];
+	return slot->tts_isnull[attphysnum - 1];
 }
 
 /*
  * slot_getattr - fetch one attribute of the slot's contents.
  */
 static inline Datum
-slot_getattr(TupleTableSlot *slot, int attnum,
+slot_getattr(TupleTableSlot *slot, int attphysnum,
 			 bool *isnull)
 {
-	AssertArg(attnum > 0);
+	AssertArg(attphysnum > 0);
 
-	if (attnum > slot->tts_nvalid)
-		slot_getsomeattrs(slot, attnum);
+	if (attphysnum > slot->tts_nvalid)
+		slot_getsomeattrs(slot, attphysnum);
 
-	*isnull = slot->tts_isnull[attnum - 1];
+	*isnull = slot->tts_isnull[attphysnum - 1];
 
-	return slot->tts_values[attnum - 1];
+	return slot->tts_values[attphysnum - 1];
 }
 
 /*
@@ -399,23 +399,23 @@ slot_getattr(TupleTableSlot *slot, int attnum,
  *  the slot type is the one that supports system attributes.
  */
 static inline Datum
-slot_getsysattr(TupleTableSlot *slot, int attnum, bool *isnull)
+slot_getsysattr(TupleTableSlot *slot, int attphysnum, bool *isnull)
 {
-	AssertArg(attnum < 0);		/* caller error */
+	AssertArg(attphysnum < 0);		/* caller error */
 
-	if (attnum == TableOidAttributeNumber)
+	if (attphysnum == TableOidAttributeNumber)
 	{
 		*isnull = false;
 		return ObjectIdGetDatum(slot->tts_tableOid);
 	}
-	else if (attnum == SelfItemPointerAttributeNumber)
+	else if (attphysnum == SelfItemPointerAttributeNumber)
 	{
 		*isnull = false;
 		return PointerGetDatum(&slot->tts_tid);
 	}
 
 	/* Fetch the system attribute from the underlying tuple. */
-	return slot->tts_ops->getsysattr(slot, attnum, isnull);
+	return slot->tts_ops->getsysattr(slot, attphysnum, isnull);
 }
 
 /*
diff --git a/src/include/foreign/foreign.h b/src/include/foreign/foreign.h
index 75538110fc..0e28214a86 100644
--- a/src/include/foreign/foreign.h
+++ b/src/include/foreign/foreign.h
@@ -76,7 +76,7 @@ extern ForeignDataWrapper *GetForeignDataWrapperByName(const char *name,
 													   bool missing_ok);
 extern ForeignTable *GetForeignTable(Oid relid);
 
-extern List *GetForeignColumnOptions(Oid relid, AttrNumber attnum);
+extern List *GetForeignColumnOptions(Oid relid, AttrNumber attphysnum);
 
 extern Oid	get_foreign_data_wrapper_oid(const char *fdwname, bool missing_ok);
 extern Oid	get_foreign_server_oid(const char *servername, bool missing_ok);
diff --git a/src/include/parser/parsetree.h b/src/include/parser/parsetree.h
index 3a1afffd18..0aa6de3247 100644
--- a/src/include/parser/parsetree.h
+++ b/src/include/parser/parsetree.h
@@ -35,13 +35,13 @@
  * Given an RTE and an attribute number, return the appropriate
  * variable name or alias for that attribute of that RTE.
  */
-extern char *get_rte_attribute_name(RangeTblEntry *rte, AttrNumber attnum);
+extern char *get_rte_attribute_name(RangeTblEntry *rte, AttrNumber attphysnum);
 
 /*
  * Check whether an attribute of an RTE has been dropped
  */
 extern bool get_rte_attribute_is_dropped(RangeTblEntry *rte,
-										 AttrNumber attnum);
+										 AttrNumber attphysnum);
 
 
 /* ----------------
diff --git a/src/include/utils/acl.h b/src/include/utils/acl.h
index 48f7d72add..a51586f473 100644
--- a/src/include/utils/acl.h
+++ b/src/include/utils/acl.h
@@ -234,9 +234,9 @@ extern void ExecAlterDefaultPrivilegesStmt(ParseState *pstate, AlterDefaultPrivi
 
 extern void RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid);
 
-extern AclMode pg_attribute_aclmask(Oid table_oid, AttrNumber attnum,
+extern AclMode pg_attribute_aclmask(Oid table_oid, AttrNumber attphysnum,
 									Oid roleid, AclMode mask, AclMaskHow how);
-extern AclMode pg_attribute_aclmask_ext(Oid table_oid, AttrNumber attnum,
+extern AclMode pg_attribute_aclmask_ext(Oid table_oid, AttrNumber attphysnum,
 										Oid roleid, AclMode mask,
 										AclMaskHow how, bool *is_missing);
 extern AclMode pg_class_aclmask(Oid table_oid, Oid roleid,
@@ -267,9 +267,9 @@ extern AclMode pg_foreign_server_aclmask(Oid srv_oid, Oid roleid,
 extern AclMode pg_type_aclmask(Oid type_oid, Oid roleid,
 							   AclMode mask, AclMaskHow how);
 
-extern AclResult pg_attribute_aclcheck(Oid table_oid, AttrNumber attnum,
+extern AclResult pg_attribute_aclcheck(Oid table_oid, AttrNumber attphysnum,
 									   Oid roleid, AclMode mode);
-extern AclResult pg_attribute_aclcheck_ext(Oid table_oid, AttrNumber attnum,
+extern AclResult pg_attribute_aclcheck_ext(Oid table_oid, AttrNumber attphysnum,
 										   Oid roleid, AclMode mode,
 										   bool *is_missing);
 extern AclResult pg_attribute_aclcheck_all(Oid table_oid, Oid roleid,
diff --git a/src/include/utils/attoptcache.h b/src/include/utils/attoptcache.h
index ee37af9500..1042d41503 100644
--- a/src/include/utils/attoptcache.h
+++ b/src/include/utils/attoptcache.h
@@ -23,6 +23,6 @@ typedef struct AttributeOpts
 	float8		n_distinct_inherited;
 } AttributeOpts;
 
-extern AttributeOpts *get_attribute_options(Oid spcid, int attnum);
+extern AttributeOpts *get_attribute_options(Oid spcid, int attphysnum);
 
 #endif							/* ATTOPTCACHE_H */
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index b8dd27d4a9..3f90894219 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -62,7 +62,7 @@ typedef struct AttStatsSlot
 } AttStatsSlot;
 
 /* Hook for plugins to get control in get_attavgwidth() */
-typedef int32 (*get_attavgwidth_hook_type) (Oid relid, AttrNumber attnum);
+typedef int32 (*get_attavgwidth_hook_type) (Oid relid, AttrNumber attphysnum);
 extern PGDLLIMPORT get_attavgwidth_hook_type get_attavgwidth_hook;
 
 extern bool op_in_opfamily(Oid opno, Oid opfamily);
@@ -88,14 +88,14 @@ extern bool equality_ops_are_compatible(Oid opno1, Oid opno2);
 extern bool comparison_ops_are_compatible(Oid opno1, Oid opno2);
 extern Oid	get_opfamily_proc(Oid opfamily, Oid lefttype, Oid righttype,
 							  int16 procnum);
-extern char *get_attname(Oid relid, AttrNumber attnum, bool missing_ok);
-extern AttrNumber get_attnum(Oid relid, const char *attname);
-extern int	get_attstattarget(Oid relid, AttrNumber attnum);
-extern char get_attgenerated(Oid relid, AttrNumber attnum);
-extern Oid	get_atttype(Oid relid, AttrNumber attnum);
-extern void get_atttypetypmodcoll(Oid relid, AttrNumber attnum,
+extern char *get_attname(Oid relid, AttrNumber attphysnum, bool missing_ok);
+extern AttrNumber get_attphysnum(Oid relid, const char *attname);
+extern int	get_attstattarget(Oid relid, AttrNumber attphysnum);
+extern char get_attgenerated(Oid relid, AttrNumber attphysnum);
+extern Oid	get_atttype(Oid relid, AttrNumber attphysnum);
+extern void get_atttypetypmodcoll(Oid relid, AttrNumber attphysnum,
 								  Oid *typid, int32 *typmod, Oid *collid);
-extern Datum get_attoptions(Oid relid, int16 attnum);
+extern Datum get_attoptions(Oid relid, int16 attphysnum);
 extern Oid	get_cast_oid(Oid sourcetypeid, Oid targettypeid, bool missing_ok);
 extern char *get_collation_name(Oid colloid);
 extern bool get_collation_isdeterministic(Oid colloid);
@@ -184,7 +184,7 @@ extern const struct SubscriptRoutines *getSubscriptingRoutines(Oid typid,
 extern Oid	getBaseType(Oid typid);
 extern Oid	getBaseTypeAndTypmod(Oid typid, int32 *typmod);
 extern int32 get_typavgwidth(Oid typid, int32 typmod);
-extern int32 get_attavgwidth(Oid relid, AttrNumber attnum);
+extern int32 get_attavgwidth(Oid relid, AttrNumber attphysnum);
 extern bool get_attstatsslot(AttStatsSlot *sslot, HeapTuple statstuple,
 							 int reqkind, Oid reqop, int flags);
 extern void free_attstatsslot(AttStatsSlot *sslot);
diff --git a/src/include/utils/relcache.h b/src/include/utils/relcache.h
index c93d8654bb..4733e06849 100644
--- a/src/include/utils/relcache.h
+++ b/src/include/utils/relcache.h
@@ -84,7 +84,7 @@ extern void RelationInitTableAccessMethod(Relation relation);
  * Routines to support ereport() reports of relation-related errors
  */
 extern int	errtable(Relation rel);
-extern int	errtablecol(Relation rel, int attnum);
+extern int	errtablecol(Relation rel, int attphysnum);
 extern int	errtablecolname(Relation rel, const char *colname);
 extern int	errtableconstraint(Relation rel, const char *conname);
 
diff --git a/src/include/utils/selfuncs.h b/src/include/utils/selfuncs.h
index d485b9bfcd..e7afaa14fc 100644
--- a/src/include/utils/selfuncs.h
+++ b/src/include/utils/selfuncs.h
@@ -136,7 +136,7 @@ typedef struct
 /* Hooks for plugins to get control when we ask for stats */
 typedef bool (*get_relation_stats_hook_type) (PlannerInfo *root,
 											  RangeTblEntry *rte,
-											  AttrNumber attnum,
+											  AttrNumber attphysnum,
 											  VariableStatData *vardata);
 extern PGDLLIMPORT get_relation_stats_hook_type get_relation_stats_hook;
 typedef bool (*get_index_stats_hook_type) (PlannerInfo *root,
diff --git a/src/include/utils/syscache.h b/src/include/utils/syscache.h
index 4463ea66be..a7c817a72f 100644
--- a/src/include/utils/syscache.h
+++ b/src/include/utils/syscache.h
@@ -38,7 +38,7 @@ enum SysCacheIdentifier
 	AMOPSTRATEGY,
 	AMPROCNUM,
 	ATTNAME,
-	ATTNUM,
+	ATTPHYSNUM,
 	AUTHMEMMEMROLE,
 	AUTHMEMROLEMEM,
 	AUTHNAME,
@@ -151,8 +151,8 @@ extern HeapTuple SearchSysCacheAttName(Oid relid, const char *attname);
 extern HeapTuple SearchSysCacheCopyAttName(Oid relid, const char *attname);
 extern bool SearchSysCacheExistsAttName(Oid relid, const char *attname);
 
-extern HeapTuple SearchSysCacheAttNum(Oid relid, int16 attnum);
-extern HeapTuple SearchSysCacheCopyAttNum(Oid relid, int16 attnum);
+extern HeapTuple SearchSysCacheAttNum(Oid relid, int16 attphysnum);
+extern HeapTuple SearchSysCacheCopyAttNum(Oid relid, int16 attphysnum);
 
 extern Datum SysCacheGetAttr(int cacheId, HeapTuple tup,
 							 AttrNumber attributeNumber, bool *isNull);
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index 4e6ee1c619..1a09017356 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -426,7 +426,7 @@ typedef struct PLpgSQL_recfield
 	int			recparentno;	/* dno of parent record */
 	int			nextfield;		/* dno of next child, or -1 if none */
 	uint64		rectupledescid; /* record's tupledesc ID as of last lookup */
-	ExpandedRecordFieldInfo finfo;	/* field's attnum and type info */
+	ExpandedRecordFieldInfo finfo;	/* field's attphysnum and type info */
 	/* if rectupledescid == INVALID_TUPLEDESC_IDENTIFIER, finfo isn't valid */
 } PLpgSQL_recfield;
 
diff --git a/src/test/modules/brin/expected/summarization-and-inprogress-insertion.out b/src/test/modules/brin/expected/summarization-and-inprogress-insertion.out
index 2a4755d099..92efe0b6ea 100644
--- a/src/test/modules/brin/expected/summarization-and-inprogress-insertion.out
+++ b/src/test/modules/brin/expected/summarization-and-inprogress-insertion.out
@@ -2,9 +2,9 @@ Parsed test spec with 2 sessions
 
 starting permutation: s2check s1b s2b s1i s2summ s1c s2c s2check
 step s2check: SELECT * FROM brin_page_items(get_raw_page('brinidx', 2), 'brinidx'::regclass);
-itemoffset|blknum|attnum|allnulls|hasnulls|placeholder|value   
-----------+------+------+--------+--------+-----------+--------
-         1|     0|     1|f       |f       |f          |{1 .. 1}
+itemoffset|blknum|attphysnum|allnulls|hasnulls|placeholder|value   
+----------+------+----------+--------+--------+-----------+--------
+         1|     0|         1|f       |f       |f          |{1 .. 1}
 (1 row)
 
 step s1b: BEGIN ISOLATION LEVEL REPEATABLE READ;
@@ -24,18 +24,18 @@ brin_summarize_new_values
 step s1c: COMMIT;
 step s2c: COMMIT;
 step s2check: SELECT * FROM brin_page_items(get_raw_page('brinidx', 2), 'brinidx'::regclass);
-itemoffset|blknum|attnum|allnulls|hasnulls|placeholder|value      
-----------+------+------+--------+--------+-----------+-----------
-         1|     0|     1|f       |f       |f          |{1 .. 1}   
-         2|     1|     1|f       |f       |f          |{1 .. 1000}
+itemoffset|blknum|attphysnum|allnulls|hasnulls|placeholder|value      
+----------+------+----------+--------+--------+-----------+-----------
+         1|     0|         1|f       |f       |f          |{1 .. 1}   
+         2|     1|         1|f       |f       |f          |{1 .. 1000}
 (2 rows)
 
 
 starting permutation: s2check s1b s1i s2vacuum s1c s2check
 step s2check: SELECT * FROM brin_page_items(get_raw_page('brinidx', 2), 'brinidx'::regclass);
-itemoffset|blknum|attnum|allnulls|hasnulls|placeholder|value   
-----------+------+------+--------+--------+-----------+--------
-         1|     0|     1|f       |f       |f          |{1 .. 1}
+itemoffset|blknum|attphysnum|allnulls|hasnulls|placeholder|value   
+----------+------+----------+--------+--------+-----------+--------
+         1|     0|         1|f       |f       |f          |{1 .. 1}
 (1 row)
 
 step s1b: BEGIN ISOLATION LEVEL REPEATABLE READ;
@@ -43,9 +43,9 @@ step s1i: INSERT INTO brin_iso VALUES (1000);
 step s2vacuum: VACUUM brin_iso;
 step s1c: COMMIT;
 step s2check: SELECT * FROM brin_page_items(get_raw_page('brinidx', 2), 'brinidx'::regclass);
-itemoffset|blknum|attnum|allnulls|hasnulls|placeholder|value      
-----------+------+------+--------+--------+-----------+-----------
-         1|     0|     1|f       |f       |f          |{1 .. 1}   
-         2|     1|     1|f       |f       |f          |{1 .. 1000}
+itemoffset|blknum|attphysnum|allnulls|hasnulls|placeholder|value      
+----------+------+----------+--------+--------+-----------+-----------
+         1|     0|         1|f       |f       |f          |{1 .. 1}   
+         2|     1|         1|f       |f       |f          |{1 .. 1000}
 (2 rows)
 
diff --git a/src/test/modules/test_misc/t/001_constraint_validation.pl b/src/test/modules/test_misc/t/001_constraint_validation.pl
index 3b9fc66b8e..62ef05dd08 100644
--- a/src/test/modules/test_misc/t/001_constraint_validation.pl
+++ b/src/test/modules/test_misc/t/001_constraint_validation.pl
@@ -209,7 +209,7 @@ run_sql_command(
 	c int,
 	d int,
 	e int,
-	LIKE list_parted2,  -- a will have attnum = 4
+	LIKE list_parted2,  -- a will have attphysnum = 4
 	CONSTRAINT check_b CHECK (b IS NULL OR b = \'a\'),
 	CONSTRAINT check_a CHECK (a IS NOT NULL AND a = 7)
 	);
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index 5ede56d9b5..777de22333 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -1746,8 +1746,8 @@ NOTICE:  merging multiple inherited definitions of column "name"
 create table gc1() inherits (c1);
 select relname, attname, attinhcount, attislocal
 from pg_class join pg_attribute on (pg_class.oid = pg_attribute.attrelid)
-where relname in ('p1','p2','c1','gc1') and attnum > 0 and not attisdropped
-order by relname, attnum;
+where relname in ('p1','p2','c1','gc1') and attphysnum > 0 and not attisdropped
+order by relname, attphysnum;
  relname | attname | attinhcount | attislocal 
 ---------+---------+-------------+------------
  c1      | id      |           1 | f
@@ -1789,8 +1789,8 @@ alter table dropColumnExists drop column if exists non_existing; --succeed
 NOTICE:  column "non_existing" of relation "dropcolumnexists" does not exist, skipping
 select relname, attname, attinhcount, attislocal
 from pg_class join pg_attribute on (pg_class.oid = pg_attribute.attrelid)
-where relname in ('p1','p2','c1','gc1') and attnum > 0 and not attisdropped
-order by relname, attnum;
+where relname in ('p1','p2','c1','gc1') and attphysnum > 0 and not attisdropped
+order by relname, attphysnum;
  relname | attname | attinhcount | attislocal 
 ---------+---------+-------------+------------
  c1      | id      |           1 | f
@@ -1815,8 +1815,8 @@ alter table depth0 add c text;
 NOTICE:  merging definition of column "c" for child "depth1"
 select attrelid::regclass, attname, attinhcount, attislocal
 from pg_attribute
-where attnum > 0 and attrelid::regclass in ('depth0', 'depth1', 'depth2')
-order by attrelid::regclass::text, attnum;
+where attphysnum > 0 and attrelid::regclass in ('depth0', 'depth1', 'depth2')
+order by attrelid::regclass::text, attphysnum;
  attrelid | attname | attinhcount | attislocal 
 ----------+---------+-------------+------------
  depth0   | c       |           0 | t
@@ -3915,7 +3915,7 @@ CREATE TABLE part_1 (
 );
 ALTER TABLE list_parted ATTACH PARTITION part_1 FOR VALUES IN (1);
 -- attislocal and conislocal are always false for merged attributes and constraints respectively.
-SELECT attislocal, attinhcount FROM pg_attribute WHERE attrelid = 'part_1'::regclass AND attnum > 0;
+SELECT attislocal, attinhcount FROM pg_attribute WHERE attrelid = 'part_1'::regclass AND attphysnum > 0;
  attislocal | attinhcount 
 ------------+-------------
  f          |           1
@@ -4063,7 +4063,7 @@ CREATE TABLE part_7_a_null (
 	c int,
 	d int,
 	e int,
-	LIKE list_parted2,  -- 'a' will have attnum = 4
+	LIKE list_parted2,  -- 'a' will have attphysnum = 4
 	CONSTRAINT check_b CHECK (b IS NULL OR b = 'a'),
 	CONSTRAINT check_a CHECK (a IS NOT NULL AND a = 7)
 );
@@ -4200,7 +4200,7 @@ DROP TABLE not_a_part;
 -- check that, after being detached, attinhcount/coninhcount is dropped to 0 and
 -- attislocal/conislocal is set to true
 ALTER TABLE list_parted2 DETACH PARTITION part_3_4;
-SELECT attinhcount, attislocal FROM pg_attribute WHERE attrelid = 'part_3_4'::regclass AND attnum > 0;
+SELECT attinhcount, attislocal FROM pg_attribute WHERE attrelid = 'part_3_4'::regclass AND attphysnum > 0;
  attinhcount | attislocal 
 -------------+------------
            0 | t
@@ -4359,19 +4359,19 @@ alter table p11 drop a;
 alter table p11 add a int;
 alter table p11 drop a;
 alter table p11 add a int not null;
--- attnum for key attribute 'a' is different in p, p1, and p11
-select attrelid::regclass, attname, attnum
+-- attphysnum for key attribute 'a' is different in p, p1, and p11
+select attrelid::regclass, attname, attphysnum
 from pg_attribute
 where attname = 'a'
  and (attrelid = 'p'::regclass
    or attrelid = 'p1'::regclass
    or attrelid = 'p11'::regclass)
 order by attrelid::regclass::text;
- attrelid | attname | attnum 
-----------+---------+--------
- p        | a       |      1
- p1       | a       |      2
- p11      | a       |      4
+ attrelid | attname | attphysnum 
+----------+---------+------------
+ p        | a       |          1
+ p1       | a       |          2
+ p11      | a       |          4
 (3 rows)
 
 alter table p1 attach partition p11 for values from (2) to (5);
diff --git a/src/test/regress/expected/create_index.out b/src/test/regress/expected/create_index.out
index d55aec3a1d..aef80b4c36 100644
--- a/src/test/regress/expected/create_index.out
+++ b/src/test/regress/expected/create_index.out
@@ -2684,17 +2684,17 @@ SELECT starelid::regclass, count(*) FROM pg_statistic WHERE starelid IN (
 (1 row)
 
 -- attstattarget should remain intact
-SELECT attrelid::regclass, attnum, attstattarget
+SELECT attrelid::regclass, attphysnum, attstattarget
   FROM pg_attribute WHERE attrelid IN (
     'concur_exprs_index_expr'::regclass,
     'concur_exprs_index_pred'::regclass,
     'concur_exprs_index_pred_2'::regclass)
-  ORDER BY attrelid::regclass::text, attnum;
-         attrelid          | attnum | attstattarget 
----------------------------+--------+---------------
- concur_exprs_index_expr   |      1 |           100
- concur_exprs_index_pred   |      1 |            -1
- concur_exprs_index_pred_2 |      1 |            -1
+  ORDER BY attrelid::regclass::text, attphysnum;
+         attrelid          | attphysnum | attstattarget 
+---------------------------+------------+---------------
+ concur_exprs_index_expr   |          1 |           100
+ concur_exprs_index_pred   |          1 |            -1
+ concur_exprs_index_pred_2 |          1 |            -1
 (3 rows)
 
 DROP TABLE concur_exprs_tab;
diff --git a/src/test/regress/expected/create_table.out b/src/test/regress/expected/create_table.out
index 4407a017a9..0d93f2c5bb 100644
--- a/src/test/regress/expected/create_table.out
+++ b/src/test/regress/expected/create_table.out
@@ -742,8 +742,8 @@ CREATE TABLE parted (
 CREATE TABLE part_a PARTITION OF parted FOR VALUES IN ('a');
 -- only inherited attributes (never local ones)
 SELECT attname, attislocal, attinhcount FROM pg_attribute
-  WHERE attrelid = 'part_a'::regclass and attnum > 0
-  ORDER BY attnum;
+  WHERE attrelid = 'part_a'::regclass and attphysnum > 0
+  ORDER BY attphysnum;
  attname | attislocal | attinhcount 
 ---------+------------+-------------
  a       | f          |           1
diff --git a/src/test/regress/expected/create_type.out b/src/test/regress/expected/create_type.out
index 0dfc88c1c8..53b998b33f 100644
--- a/src/test/regress/expected/create_type.out
+++ b/src/test/regress/expected/create_type.out
@@ -214,7 +214,7 @@ LINE 1: CREATE TEMP TABLE mytab (foo widget(42,13,7));
                                      ^
 CREATE TEMP TABLE mytab (foo widget(42,13));
 SELECT format_type(atttypid,atttypmod) FROM pg_attribute
-WHERE attrelid = 'mytab'::regclass AND attnum > 0;
+WHERE attrelid = 'mytab'::regclass AND attphysnum > 0;
   format_type  
 ---------------
  widget(42,13)
diff --git a/src/test/regress/expected/foreign_key.out b/src/test/regress/expected/foreign_key.out
index da26f083bc..584630b8a7 100644
--- a/src/test/regress/expected/foreign_key.out
+++ b/src/test/regress/expected/foreign_key.out
@@ -1466,7 +1466,7 @@ explain (costs off) delete from t1 where a = 1;
 (10 rows)
 
 delete from t1 where a = 1;
--- Test a primary key with attributes located in later attnum positions
+-- Test a primary key with attributes located in later attphysnum positions
 -- compared to the fk attributes.
 create table pktable2 (a int, b int, c int, d int, e int, primary key (d, e));
 create table fktable2 (d int, e int, foreign key (d, e) references pktable2);
diff --git a/src/test/regress/expected/indexing.out b/src/test/regress/expected/indexing.out
index 193f780191..d0d117a5c7 100644
--- a/src/test/regress/expected/indexing.out
+++ b/src/test/regress/expected/indexing.out
@@ -815,18 +815,18 @@ Partition of: idxpart FOR VALUES FROM (0) TO (1000)
 Indexes:
     "idxpart1_col_keep_idx" btree (col_keep)
 
-select attrelid::regclass, attname, attnum from pg_attribute
-  where attrelid::regclass::text like 'idxpart%' and attnum > 0
-  order by attrelid::regclass, attnum;
-       attrelid        |           attname            | attnum 
------------------------+------------------------------+--------
- idxpart1              | ........pg.dropped.1........ |      1
- idxpart1              | ........pg.dropped.2........ |      2
- idxpart1              | col_keep                     |      3
- idxpart1              | ........pg.dropped.4........ |      4
- idxpart1_col_keep_idx | col_keep                     |      1
- idxpart               | col_keep                     |      1
- idxpart_col_keep_idx  | col_keep                     |      1
+select attrelid::regclass, attname, attphysnum from pg_attribute
+  where attrelid::regclass::text like 'idxpart%' and attphysnum > 0
+  order by attrelid::regclass, attphysnum;
+       attrelid        |           attname            | attphysnum 
+-----------------------+------------------------------+------------
+ idxpart1              | ........pg.dropped.1........ |          1
+ idxpart1              | ........pg.dropped.2........ |          2
+ idxpart1              | col_keep                     |          3
+ idxpart1              | ........pg.dropped.4........ |          4
+ idxpart1_col_keep_idx | col_keep                     |          1
+ idxpart               | col_keep                     |          1
+ idxpart_col_keep_idx  | col_keep                     |          1
 (7 rows)
 
 drop table idxpart;
@@ -858,18 +858,18 @@ Partition of: idxpart FOR VALUES FROM (0) TO (1000)
 Indexes:
     "idxpart1_col_keep_idx" btree (col_keep)
 
-select attrelid::regclass, attname, attnum from pg_attribute
-  where attrelid::regclass::text like 'idxpart%' and attnum > 0
-  order by attrelid::regclass, attnum;
-       attrelid        |           attname            | attnum 
------------------------+------------------------------+--------
- idxpart               | ........pg.dropped.1........ |      1
- idxpart               | ........pg.dropped.2........ |      2
- idxpart               | col_keep                     |      3
- idxpart               | ........pg.dropped.4........ |      4
- idxpart1              | col_keep                     |      1
- idxpart1_col_keep_idx | col_keep                     |      1
- idxpart_col_keep_idx  | col_keep                     |      1
+select attrelid::regclass, attname, attphysnum from pg_attribute
+  where attrelid::regclass::text like 'idxpart%' and attphysnum > 0
+  order by attrelid::regclass, attphysnum;
+       attrelid        |           attname            | attphysnum 
+-----------------------+------------------------------+------------
+ idxpart               | ........pg.dropped.1........ |          1
+ idxpart               | ........pg.dropped.2........ |          2
+ idxpart               | col_keep                     |          3
+ idxpart               | ........pg.dropped.4........ |          4
+ idxpart1              | col_keep                     |          1
+ idxpart1_col_keep_idx | col_keep                     |          1
+ idxpart_col_keep_idx  | col_keep                     |          1
 (7 rows)
 
 drop table idxpart;
diff --git a/src/test/regress/expected/inherit.out b/src/test/regress/expected/inherit.out
index 2d49e765de..84bc012f30 100644
--- a/src/test/regress/expected/inherit.out
+++ b/src/test/regress/expected/inherit.out
@@ -1106,7 +1106,7 @@ SELECT a.attrelid::regclass, a.attname, a.attinhcount, e.expected
   FROM (SELECT inhrelid, count(*) AS expected FROM pg_inherits
         WHERE inhparent IN (SELECT inhrelid FROM r) GROUP BY inhrelid) e
   JOIN pg_attribute a ON e.inhrelid = a.attrelid WHERE NOT attislocal
-  ORDER BY a.attrelid::regclass::name, a.attnum;
+  ORDER BY a.attrelid::regclass::name, a.attphysnum;
  attrelid | attname | attinhcount | expected 
 ----------+---------+-------------+----------
  inht2    | aaaa    |           1 |        1
diff --git a/src/test/regress/expected/insert.out b/src/test/regress/expected/insert.out
index dd4354fc7d..491d7ff28e 100644
--- a/src/test/regress/expected/insert.out
+++ b/src/test/regress/expected/insert.out
@@ -497,19 +497,19 @@ alter table mlparted11 drop a;
 alter table mlparted11 add a int;
 alter table mlparted11 drop a;
 alter table mlparted11 add a int not null;
--- attnum for key attribute 'a' is different in mlparted, mlparted1, and mlparted11
-select attrelid::regclass, attname, attnum
+-- attphysnum for key attribute 'a' is different in mlparted, mlparted1, and mlparted11
+select attrelid::regclass, attname, attphysnum
 from pg_attribute
 where attname = 'a'
  and (attrelid = 'mlparted'::regclass
    or attrelid = 'mlparted1'::regclass
    or attrelid = 'mlparted11'::regclass)
 order by attrelid::regclass::text;
-  attrelid  | attname | attnum 
-------------+---------+--------
- mlparted   | a       |      1
- mlparted1  | a       |      2
- mlparted11 | a       |      4
+  attrelid  | attname | attphysnum 
+------------+---------+------------
+ mlparted   | a       |          1
+ mlparted1  | a       |          2
+ mlparted11 | a       |          4
 (3 rows)
 
 alter table mlparted1 attach partition mlparted11 for values from (2) to (5);
diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index 2538bd6a79..cab82b3093 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -4944,8 +4944,8 @@ HINT:  Perhaps you meant to reference the column "t1.unique1" or the column "t2.
 --
 select atts.relid::regclass, s.* from pg_stats s join
     pg_attribute a on s.attname = a.attname and s.tablename =
-    a.attrelid::regclass::text join (select unnest(indkey) attnum,
-    indexrelid from pg_index i) atts on atts.attnum = a.attnum where
+    a.attrelid::regclass::text join (select unnest(indkey) attphysnum,
+    indexrelid from pg_index i) atts on atts.attphysnum = a.attphysnum where
     schemaname != 'pg_catalog';
 ERROR:  column atts.relid does not exist
 LINE 1: select atts.relid::regclass, s.* from pg_stats s join
diff --git a/src/test/regress/expected/oidjoins.out b/src/test/regress/expected/oidjoins.out
index 215eb899be..5acd051618 100644
--- a/src/test/regress/expected/oidjoins.out
+++ b/src/test/regress/expected/oidjoins.out
@@ -83,7 +83,7 @@ NOTICE:  checking pg_class {reltablespace} => pg_tablespace {oid}
 NOTICE:  checking pg_class {reltoastrelid} => pg_class {oid}
 NOTICE:  checking pg_class {relrewrite} => pg_class {oid}
 NOTICE:  checking pg_attrdef {adrelid} => pg_class {oid}
-NOTICE:  checking pg_attrdef {adrelid,adnum} => pg_attribute {attrelid,attnum}
+NOTICE:  checking pg_attrdef {adrelid,adnum} => pg_attribute {attrelid,attphysnum}
 NOTICE:  checking pg_constraint {connamespace} => pg_namespace {oid}
 NOTICE:  checking pg_constraint {conrelid} => pg_class {oid}
 NOTICE:  checking pg_constraint {contypid} => pg_type {oid}
@@ -94,15 +94,15 @@ NOTICE:  checking pg_constraint {conpfeqop} => pg_operator {oid}
 NOTICE:  checking pg_constraint {conppeqop} => pg_operator {oid}
 NOTICE:  checking pg_constraint {conffeqop} => pg_operator {oid}
 NOTICE:  checking pg_constraint {conexclop} => pg_operator {oid}
-NOTICE:  checking pg_constraint {conrelid,conkey} => pg_attribute {attrelid,attnum}
-NOTICE:  checking pg_constraint {confrelid,confkey} => pg_attribute {attrelid,attnum}
+NOTICE:  checking pg_constraint {conrelid,conkey} => pg_attribute {attrelid,attphysnum}
+NOTICE:  checking pg_constraint {confrelid,confkey} => pg_attribute {attrelid,attphysnum}
 NOTICE:  checking pg_inherits {inhrelid} => pg_class {oid}
 NOTICE:  checking pg_inherits {inhparent} => pg_class {oid}
 NOTICE:  checking pg_index {indexrelid} => pg_class {oid}
 NOTICE:  checking pg_index {indrelid} => pg_class {oid}
 NOTICE:  checking pg_index {indcollation} => pg_collation {oid}
 NOTICE:  checking pg_index {indclass} => pg_opclass {oid}
-NOTICE:  checking pg_index {indrelid,indkey} => pg_attribute {attrelid,attnum}
+NOTICE:  checking pg_index {indrelid,indkey} => pg_attribute {attrelid,attphysnum}
 NOTICE:  checking pg_operator {oprnamespace} => pg_namespace {oid}
 NOTICE:  checking pg_operator {oprowner} => pg_authid {oid}
 NOTICE:  checking pg_operator {oprleft} => pg_type {oid}
@@ -162,11 +162,11 @@ NOTICE:  checking pg_statistic {stacoll2} => pg_collation {oid}
 NOTICE:  checking pg_statistic {stacoll3} => pg_collation {oid}
 NOTICE:  checking pg_statistic {stacoll4} => pg_collation {oid}
 NOTICE:  checking pg_statistic {stacoll5} => pg_collation {oid}
-NOTICE:  checking pg_statistic {starelid,staattnum} => pg_attribute {attrelid,attnum}
+NOTICE:  checking pg_statistic {starelid,staattnum} => pg_attribute {attrelid,attphysnum}
 NOTICE:  checking pg_statistic_ext {stxrelid} => pg_class {oid}
 NOTICE:  checking pg_statistic_ext {stxnamespace} => pg_namespace {oid}
 NOTICE:  checking pg_statistic_ext {stxowner} => pg_authid {oid}
-NOTICE:  checking pg_statistic_ext {stxrelid,stxkeys} => pg_attribute {attrelid,attnum}
+NOTICE:  checking pg_statistic_ext {stxrelid,stxkeys} => pg_attribute {attrelid,attphysnum}
 NOTICE:  checking pg_statistic_ext_data {stxoid} => pg_statistic_ext {oid}
 NOTICE:  checking pg_rewrite {ev_class} => pg_class {oid}
 NOTICE:  checking pg_trigger {tgrelid} => pg_class {oid}
@@ -175,7 +175,7 @@ NOTICE:  checking pg_trigger {tgfoid} => pg_proc {oid}
 NOTICE:  checking pg_trigger {tgconstrrelid} => pg_class {oid}
 NOTICE:  checking pg_trigger {tgconstrindid} => pg_class {oid}
 NOTICE:  checking pg_trigger {tgconstraint} => pg_constraint {oid}
-NOTICE:  checking pg_trigger {tgrelid,tgattr} => pg_attribute {attrelid,attnum}
+NOTICE:  checking pg_trigger {tgrelid,tgattr} => pg_attribute {attrelid,attphysnum}
 NOTICE:  checking pg_event_trigger {evtowner} => pg_authid {oid}
 NOTICE:  checking pg_event_trigger {evtfoid} => pg_proc {oid}
 NOTICE:  checking pg_description {classoid} => pg_class {oid}
@@ -243,7 +243,7 @@ NOTICE:  checking pg_partitioned_table {partrelid} => pg_class {oid}
 NOTICE:  checking pg_partitioned_table {partdefid} => pg_class {oid}
 NOTICE:  checking pg_partitioned_table {partclass} => pg_opclass {oid}
 NOTICE:  checking pg_partitioned_table {partcollation} => pg_collation {oid}
-NOTICE:  checking pg_partitioned_table {partrelid,partattrs} => pg_attribute {attrelid,attnum}
+NOTICE:  checking pg_partitioned_table {partrelid,partattrs} => pg_attribute {attrelid,attphysnum}
 NOTICE:  checking pg_range {rngtypid} => pg_type {oid}
 NOTICE:  checking pg_range {rngsubtype} => pg_type {oid}
 NOTICE:  checking pg_range {rngmultitypid} => pg_type {oid}
diff --git a/src/test/regress/expected/opr_sanity.out b/src/test/regress/expected/opr_sanity.out
index 86d755aa44..12e883ff79 100644
--- a/src/test/regress/expected/opr_sanity.out
+++ b/src/test/regress/expected/opr_sanity.out
@@ -2216,7 +2216,7 @@ FROM (SELECT indexrelid, indrelid, unnest(indkey) as ikey,
       FROM pg_index) ss,
       pg_attribute a,
       pg_opclass opc
-WHERE a.attrelid = indrelid AND a.attnum = ikey AND opc.oid = iclass AND
+WHERE a.attrelid = indrelid AND a.attphysnum = ikey AND opc.oid = iclass AND
       (NOT binary_coercible(atttypid, opcintype) OR icoll != attcollation);
  indexrelid | indrelid | attname | atttypid | opcname 
 ------------+----------+---------+----------+---------
@@ -2232,7 +2232,7 @@ FROM (SELECT indexrelid, indrelid, unnest(indkey) as ikey,
       WHERE indrelid < 16384) ss,
       pg_attribute a,
       pg_opclass opc
-WHERE a.attrelid = indrelid AND a.attnum = ikey AND opc.oid = iclass AND
+WHERE a.attrelid = indrelid AND a.attphysnum = ikey AND opc.oid = iclass AND
       (opcintype != atttypid OR icoll != attcollation)
 ORDER BY 1;
         indexrelid        |   indrelid   | attname  | atttypid | opcname 
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 60acbd1241..195fa9f287 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -241,8 +241,8 @@ SELECT 3 AS x, 'Hello', 4 AS y, true AS "dirty\name" \gdesc \g
 create temporary table gexec_test(a int, b text, c date, d float);
 select format('create index on gexec_test(%I)', attname)
 from pg_attribute
-where attrelid = 'gexec_test'::regclass and attnum > 0
-order by attnum
+where attrelid = 'gexec_test'::regclass and attphysnum > 0
+order by attphysnum
 \gexec
 create index on gexec_test(a)
 create index on gexec_test(b)
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index fc3cde3226..fcf522dad8 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1438,14 +1438,14 @@ pg_prepared_xacts| SELECT p.transaction,
 pg_publication_tables| SELECT p.pubname,
     n.nspname AS schemaname,
     c.relname AS tablename,
-    ( SELECT array_agg(a.attname ORDER BY a.attnum) AS array_agg
+    ( SELECT array_agg(a.attname ORDER BY a.attphysnum) AS array_agg
            FROM (unnest(
                 CASE
                     WHEN (gpt.attrs IS NOT NULL) THEN (gpt.attrs)::integer[]
                     ELSE ( SELECT array_agg(g.g) AS array_agg
                        FROM generate_series(1, (c.relnatts)::integer) g(g))
                 END) k(k)
-             JOIN pg_attribute a ON (((a.attrelid = gpt.relid) AND (a.attnum = k.k))))) AS attnames,
+             JOIN pg_attribute a ON (((a.attrelid = gpt.relid) AND (a.attphysnum = k.k))))) AS attnames,
     pg_get_expr(gpt.qual, gpt.relid) AS rowfilter
    FROM pg_publication p,
     LATERAL pg_get_publication_tables((p.pubname)::text) gpt(relid, attrs, qual),
@@ -1534,7 +1534,7 @@ UNION ALL
     l.label
    FROM (((pg_seclabel l
      JOIN pg_class rel ON (((l.classoid = rel.tableoid) AND (l.objoid = rel.oid))))
-     JOIN pg_attribute att ON (((rel.oid = att.attrelid) AND (l.objsubid = att.attnum))))
+     JOIN pg_attribute att ON (((rel.oid = att.attrelid) AND (l.objsubid = att.attphysnum))))
      JOIN pg_namespace nsp ON ((rel.relnamespace = nsp.oid)))
   WHERE (l.objsubid <> 0)
 UNION ALL
@@ -2428,17 +2428,17 @@ pg_stats| SELECT n.nspname AS schemaname,
         END AS elem_count_histogram
    FROM (((pg_statistic s
      JOIN pg_class c ON ((c.oid = s.starelid)))
-     JOIN pg_attribute a ON (((c.oid = a.attrelid) AND (a.attnum = s.staattnum))))
+     JOIN pg_attribute a ON (((c.oid = a.attrelid) AND (a.attphysnum = s.staattnum))))
      LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace)))
-  WHERE ((NOT a.attisdropped) AND has_column_privilege(c.oid, a.attnum, 'select'::text) AND ((c.relrowsecurity = false) OR (NOT row_security_active(c.oid))));
+  WHERE ((NOT a.attisdropped) AND has_column_privilege(c.oid, a.attphysnum, 'select'::text) AND ((c.relrowsecurity = false) OR (NOT row_security_active(c.oid))));
 pg_stats_ext| SELECT cn.nspname AS schemaname,
     c.relname AS tablename,
     sn.nspname AS statistics_schemaname,
     s.stxname AS statistics_name,
     pg_get_userbyid(s.stxowner) AS statistics_owner,
-    ( SELECT array_agg(a.attname ORDER BY a.attnum) AS array_agg
+    ( SELECT array_agg(a.attname ORDER BY a.attphysnum) AS array_agg
            FROM (unnest(s.stxkeys) k(k)
-             JOIN pg_attribute a ON (((a.attrelid = s.stxrelid) AND (a.attnum = k.k))))) AS attnames,
+             JOIN pg_attribute a ON (((a.attrelid = s.stxrelid) AND (a.attphysnum = k.k))))) AS attnames,
     pg_get_statisticsobjdef_expressions(s.oid) AS exprs,
     s.stxkind AS kinds,
     sd.stxdinherit AS inherited,
@@ -2460,8 +2460,8 @@ pg_stats_ext| SELECT cn.nspname AS schemaname,
            FROM pg_mcv_list_items(sd.stxdmcv) pg_mcv_list_items(index, "values", nulls, frequency, base_frequency)) m ON ((sd.stxdmcv IS NOT NULL)))
   WHERE ((NOT (EXISTS ( SELECT 1
            FROM (unnest(s.stxkeys) k(k)
-             JOIN pg_attribute a ON (((a.attrelid = s.stxrelid) AND (a.attnum = k.k))))
-          WHERE (NOT has_column_privilege(c.oid, a.attnum, 'select'::text))))) AND ((c.relrowsecurity = false) OR (NOT row_security_active(c.oid))));
+             JOIN pg_attribute a ON (((a.attrelid = s.stxrelid) AND (a.attphysnum = k.k))))
+          WHERE (NOT has_column_privilege(c.oid, a.attphysnum, 'select'::text))))) AND ((c.relrowsecurity = false) OR (NOT row_security_active(c.oid))));
 pg_stats_ext_exprs| SELECT cn.nspname AS schemaname,
     c.relname AS tablename,
     sn.nspname AS statistics_schemaname,
diff --git a/src/test/regress/expected/sanity_check.out b/src/test/regress/expected/sanity_check.out
index c5c675b750..7714c49e2f 100644
--- a/src/test/regress/expected/sanity_check.out
+++ b/src/test/regress/expected/sanity_check.out
@@ -10,7 +10,7 @@ SELECT relname, nspname
  WHERE relkind = 'r' and c.oid < 16384
      AND ((nspname ~ '^pg_') IS NOT FALSE)
      AND NOT EXISTS (SELECT 1 FROM pg_index i WHERE indrelid = c.oid
-                     AND indkey[0] = a.attnum AND indnatts = 1
+                     AND indkey[0] = a.attphysnum AND indnatts = 1
                      AND indisunique AND indimmediate);
  relname | nspname 
 ---------+---------
@@ -39,8 +39,8 @@ WITH check_columns AS (
    SELECT t.oid
     FROM pg_type t JOIN pg_attribute pa ON t.oid = pa.atttypid
     WHERE pa.attrelid = a.attrelid AND
-          pa.attnum > 0 AND pa.attnum < a.attnum
-    ORDER BY pa.attnum) AS coltypes
+          pa.attphysnum > 0 AND pa.attphysnum < a.attphysnum
+    ORDER BY pa.attphysnum) AS coltypes
  FROM pg_attribute a JOIN pg_class c ON c.oid = attrelid
   JOIN pg_namespace n ON c.relnamespace = n.oid
  WHERE attalign = 'd' AND relkind = 'r' AND
diff --git a/src/test/regress/expected/type_sanity.out b/src/test/regress/expected/type_sanity.out
index d3ac08c9ee..51fcda3e6f 100644
--- a/src/test/regress/expected/type_sanity.out
+++ b/src/test/regress/expected/type_sanity.out
@@ -578,17 +578,17 @@ WHERE pc.relkind IN ('r', 't', 'm') and
 -- Look for illegal values in pg_attribute fields
 SELECT a1.attrelid, a1.attname
 FROM pg_attribute as a1
-WHERE a1.attrelid = 0 OR a1.atttypid = 0 OR a1.attnum = 0 OR
+WHERE a1.attrelid = 0 OR a1.atttypid = 0 OR a1.attphysnum = 0 OR
     a1.attcacheoff != -1 OR a1.attinhcount < 0 OR
     (a1.attinhcount = 0 AND NOT a1.attislocal);
  attrelid | attname 
 ----------+---------
 (0 rows)
 
--- Cross-check attnum against parent relation
+-- Cross-check attphysnum against parent relation
 SELECT a1.attrelid, a1.attname, c1.oid, c1.relname
 FROM pg_attribute AS a1, pg_class AS c1
-WHERE a1.attrelid = c1.oid AND a1.attnum > c1.relnatts;
+WHERE a1.attrelid = c1.oid AND a1.attphysnum > c1.relnatts;
  attrelid | attname | oid | relname 
 ----------+---------+-----+---------
 (0 rows)
@@ -598,7 +598,7 @@ WHERE a1.attrelid = c1.oid AND a1.attnum > c1.relnatts;
 SELECT c1.oid, c1.relname
 FROM pg_class AS c1
 WHERE c1.relnatts != (SELECT count(*) FROM pg_attribute AS a1
-                      WHERE a1.attrelid = c1.oid AND a1.attnum > 0);
+                      WHERE a1.attrelid = c1.oid AND a1.attphysnum > 0);
  oid | relname 
 -----+---------
 (0 rows)
@@ -765,7 +765,7 @@ SELECT oid, typname, typtype, typelem, typarray
     AND NOT EXISTS (SELECT 1
                     FROM pg_attribute a
                     WHERE a.atttypid=t.oid AND
-                          a.attnum > 0 AND
+                          a.attphysnum > 0 AND
                           a.attrelid='tab_core_types'::regclass);
  oid | typname | typtype | typelem | typarray 
 -----+---------+---------+---------+----------
diff --git a/src/test/regress/regress.c b/src/test/regress/regress.c
index ba3532a51e..f34c8474b4 100644
--- a/src/test/regress/regress.c
+++ b/src/test/regress/regress.c
@@ -272,7 +272,7 @@ ttdummy(PG_FUNCTION_ARGS)
 	TriggerData *trigdata = (TriggerData *) fcinfo->context;
 	Trigger    *trigger;		/* to get trigger name */
 	char	  **args;			/* arguments */
-	int			attnum[2];		/* fnumbers of start/stop columns */
+	int			attphysnum[2];		/* fnumbers of start/stop columns */
 	Datum		oldon,
 				oldoff;
 	Datum		newon,
@@ -325,29 +325,29 @@ ttdummy(PG_FUNCTION_ARGS)
 
 	for (i = 0; i < 2; i++)
 	{
-		attnum[i] = SPI_fnumber(tupdesc, args[i]);
-		if (attnum[i] <= 0)
+		attphysnum[i] = SPI_fnumber(tupdesc, args[i]);
+		if (attphysnum[i] <= 0)
 			elog(ERROR, "ttdummy (%s): there is no attribute %s",
 				 relname, args[i]);
-		if (SPI_gettypeid(tupdesc, attnum[i]) != INT4OID)
+		if (SPI_gettypeid(tupdesc, attphysnum[i]) != INT4OID)
 			elog(ERROR, "ttdummy (%s): attribute %s must be of integer type",
 				 relname, args[i]);
 	}
 
-	oldon = SPI_getbinval(trigtuple, tupdesc, attnum[0], &isnull);
+	oldon = SPI_getbinval(trigtuple, tupdesc, attphysnum[0], &isnull);
 	if (isnull)
 		elog(ERROR, "ttdummy (%s): %s must be NOT NULL", relname, args[0]);
 
-	oldoff = SPI_getbinval(trigtuple, tupdesc, attnum[1], &isnull);
+	oldoff = SPI_getbinval(trigtuple, tupdesc, attphysnum[1], &isnull);
 	if (isnull)
 		elog(ERROR, "ttdummy (%s): %s must be NOT NULL", relname, args[1]);
 
 	if (newtuple != NULL)		/* UPDATE */
 	{
-		newon = SPI_getbinval(newtuple, tupdesc, attnum[0], &isnull);
+		newon = SPI_getbinval(newtuple, tupdesc, attphysnum[0], &isnull);
 		if (isnull)
 			elog(ERROR, "ttdummy (%s): %s must be NOT NULL", relname, args[0]);
-		newoff = SPI_getbinval(newtuple, tupdesc, attnum[1], &isnull);
+		newoff = SPI_getbinval(newtuple, tupdesc, attphysnum[1], &isnull);
 		if (isnull)
 			elog(ERROR, "ttdummy (%s): %s must be NOT NULL", relname, args[1]);
 
@@ -390,16 +390,16 @@ ttdummy(PG_FUNCTION_ARGS)
 	/* change date column(s) */
 	if (newtuple)				/* UPDATE */
 	{
-		cvals[attnum[0] - 1] = newoff;	/* start_date eq current date */
-		cnulls[attnum[0] - 1] = ' ';
-		cvals[attnum[1] - 1] = TTDUMMY_INFINITY;	/* stop_date eq INFINITY */
-		cnulls[attnum[1] - 1] = ' ';
+		cvals[attphysnum[0] - 1] = newoff;	/* start_date eq current date */
+		cnulls[attphysnum[0] - 1] = ' ';
+		cvals[attphysnum[1] - 1] = TTDUMMY_INFINITY;	/* stop_date eq INFINITY */
+		cnulls[attphysnum[1] - 1] = ' ';
 	}
 	else
 		/* DELETE */
 	{
-		cvals[attnum[1] - 1] = newoff;	/* stop_date eq current date */
-		cnulls[attnum[1] - 1] = ' ';
+		cvals[attphysnum[1] - 1] = newoff;	/* stop_date eq current date */
+		cnulls[attphysnum[1] - 1] = ' ';
 	}
 
 	/* if there is no plan ... */
@@ -442,7 +442,7 @@ ttdummy(PG_FUNCTION_ARGS)
 
 	/* Tuple to return to upper Executor ... */
 	if (newtuple)				/* UPDATE */
-		rettuple = SPI_modifytuple(rel, trigtuple, 1, &(attnum[1]), &newoff, NULL);
+		rettuple = SPI_modifytuple(rel, trigtuple, 1, &(attphysnum[1]), &newoff, NULL);
 	else						/* DELETE */
 		rettuple = trigtuple;
 
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
index 52001e3135..6784da0f4c 100644
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -1250,8 +1250,8 @@ create table gc1() inherits (c1);
 
 select relname, attname, attinhcount, attislocal
 from pg_class join pg_attribute on (pg_class.oid = pg_attribute.attrelid)
-where relname in ('p1','p2','c1','gc1') and attnum > 0 and not attisdropped
-order by relname, attnum;
+where relname in ('p1','p2','c1','gc1') and attphysnum > 0 and not attisdropped
+order by relname, attphysnum;
 
 -- should work
 alter table only p1 drop column name;
@@ -1273,8 +1273,8 @@ alter table dropColumnExists drop column if exists non_existing; --succeed
 
 select relname, attname, attinhcount, attislocal
 from pg_class join pg_attribute on (pg_class.oid = pg_attribute.attrelid)
-where relname in ('p1','p2','c1','gc1') and attnum > 0 and not attisdropped
-order by relname, attnum;
+where relname in ('p1','p2','c1','gc1') and attphysnum > 0 and not attisdropped
+order by relname, attphysnum;
 
 drop table p1, p2 cascade;
 
@@ -1287,8 +1287,8 @@ alter table depth0 add c text;
 
 select attrelid::regclass, attname, attinhcount, attislocal
 from pg_attribute
-where attnum > 0 and attrelid::regclass in ('depth0', 'depth1', 'depth2')
-order by attrelid::regclass::text, attnum;
+where attphysnum > 0 and attrelid::regclass in ('depth0', 'depth1', 'depth2')
+order by attrelid::regclass::text, attphysnum;
 
 -- test renumbering of child-table columns in inherited operations
 
@@ -2434,7 +2434,7 @@ CREATE TABLE part_1 (
 );
 ALTER TABLE list_parted ATTACH PARTITION part_1 FOR VALUES IN (1);
 -- attislocal and conislocal are always false for merged attributes and constraints respectively.
-SELECT attislocal, attinhcount FROM pg_attribute WHERE attrelid = 'part_1'::regclass AND attnum > 0;
+SELECT attislocal, attinhcount FROM pg_attribute WHERE attrelid = 'part_1'::regclass AND attphysnum > 0;
 SELECT conislocal, coninhcount FROM pg_constraint WHERE conrelid = 'part_1'::regclass AND conname = 'check_a';
 
 -- check that the new partition won't overlap with an existing partition
@@ -2580,7 +2580,7 @@ CREATE TABLE part_7_a_null (
 	c int,
 	d int,
 	e int,
-	LIKE list_parted2,  -- 'a' will have attnum = 4
+	LIKE list_parted2,  -- 'a' will have attphysnum = 4
 	CONSTRAINT check_b CHECK (b IS NULL OR b = 'a'),
 	CONSTRAINT check_a CHECK (a IS NOT NULL AND a = 7)
 );
@@ -2707,7 +2707,7 @@ DROP TABLE not_a_part;
 -- check that, after being detached, attinhcount/coninhcount is dropped to 0 and
 -- attislocal/conislocal is set to true
 ALTER TABLE list_parted2 DETACH PARTITION part_3_4;
-SELECT attinhcount, attislocal FROM pg_attribute WHERE attrelid = 'part_3_4'::regclass AND attnum > 0;
+SELECT attinhcount, attislocal FROM pg_attribute WHERE attrelid = 'part_3_4'::regclass AND attphysnum > 0;
 SELECT coninhcount, conislocal FROM pg_constraint WHERE conrelid = 'part_3_4'::regclass AND conname = 'check_a';
 DROP TABLE part_3_4;
 
@@ -2816,8 +2816,8 @@ alter table p11 drop a;
 alter table p11 add a int;
 alter table p11 drop a;
 alter table p11 add a int not null;
--- attnum for key attribute 'a' is different in p, p1, and p11
-select attrelid::regclass, attname, attnum
+-- attphysnum for key attribute 'a' is different in p, p1, and p11
+select attrelid::regclass, attname, attphysnum
 from pg_attribute
 where attname = 'a'
  and (attrelid = 'p'::regclass
diff --git a/src/test/regress/sql/create_index.sql b/src/test/regress/sql/create_index.sql
index d8fded3d93..c2b0f58c6b 100644
--- a/src/test/regress/sql/create_index.sql
+++ b/src/test/regress/sql/create_index.sql
@@ -1140,12 +1140,12 @@ SELECT starelid::regclass, count(*) FROM pg_statistic WHERE starelid IN (
   'concur_exprs_index_pred_2'::regclass)
   GROUP BY starelid ORDER BY starelid::regclass::text;
 -- attstattarget should remain intact
-SELECT attrelid::regclass, attnum, attstattarget
+SELECT attrelid::regclass, attphysnum, attstattarget
   FROM pg_attribute WHERE attrelid IN (
     'concur_exprs_index_expr'::regclass,
     'concur_exprs_index_pred'::regclass,
     'concur_exprs_index_pred_2'::regclass)
-  ORDER BY attrelid::regclass::text, attnum;
+  ORDER BY attrelid::regclass::text, attphysnum;
 DROP TABLE concur_exprs_tab;
 
 -- Temporary tables and on-commit actions, where CONCURRENTLY is ignored.
diff --git a/src/test/regress/sql/create_table.sql b/src/test/regress/sql/create_table.sql
index 5175f404f7..b1d935c0fe 100644
--- a/src/test/regress/sql/create_table.sql
+++ b/src/test/regress/sql/create_table.sql
@@ -513,8 +513,8 @@ CREATE TABLE part_a PARTITION OF parted FOR VALUES IN ('a');
 
 -- only inherited attributes (never local ones)
 SELECT attname, attislocal, attinhcount FROM pg_attribute
-  WHERE attrelid = 'part_a'::regclass and attnum > 0
-  ORDER BY attnum;
+  WHERE attrelid = 'part_a'::regclass and attphysnum > 0
+  ORDER BY attphysnum;
 
 -- able to specify column default, column constraint, and table constraint
 
diff --git a/src/test/regress/sql/create_type.sql b/src/test/regress/sql/create_type.sql
index c6fc4f9029..017484ec65 100644
--- a/src/test/regress/sql/create_type.sql
+++ b/src/test/regress/sql/create_type.sql
@@ -180,7 +180,7 @@ CREATE TEMP TABLE mytab (foo widget(42,13,7));     -- should fail
 CREATE TEMP TABLE mytab (foo widget(42,13));
 
 SELECT format_type(atttypid,atttypmod) FROM pg_attribute
-WHERE attrelid = 'mytab'::regclass AND attnum > 0;
+WHERE attrelid = 'mytab'::regclass AND attphysnum > 0;
 
 -- might as well exercise the widget type while we're here
 INSERT INTO mytab VALUES ('(1,2,3)'), ('(-44,5.5,12)');
diff --git a/src/test/regress/sql/foreign_key.sql b/src/test/regress/sql/foreign_key.sql
index 725a59a525..6a1118098a 100644
--- a/src/test/regress/sql/foreign_key.sql
+++ b/src/test/regress/sql/foreign_key.sql
@@ -1087,7 +1087,7 @@ create rule r1 as on delete to t1 do delete from t2 where t2.b = old.a;
 explain (costs off) delete from t1 where a = 1;
 delete from t1 where a = 1;
 
--- Test a primary key with attributes located in later attnum positions
+-- Test a primary key with attributes located in later attphysnum positions
 -- compared to the fk attributes.
 create table pktable2 (a int, b int, c int, d int, e int, primary key (d, e));
 create table fktable2 (d int, e int, foreign key (d, e) references pktable2);
diff --git a/src/test/regress/sql/indexing.sql b/src/test/regress/sql/indexing.sql
index 42f398b67c..5370452cb2 100644
--- a/src/test/regress/sql/indexing.sql
+++ b/src/test/regress/sql/indexing.sql
@@ -423,9 +423,9 @@ create index on idxpart (col_keep);
 alter table idxpart attach partition idxpart1 for values from (0) to (1000);
 \d idxpart
 \d idxpart1
-select attrelid::regclass, attname, attnum from pg_attribute
-  where attrelid::regclass::text like 'idxpart%' and attnum > 0
-  order by attrelid::regclass, attnum;
+select attrelid::regclass, attname, attphysnum from pg_attribute
+  where attrelid::regclass::text like 'idxpart%' and attphysnum > 0
+  order by attrelid::regclass, attphysnum;
 drop table idxpart;
 
 -- Column number mapping: dropped columns in the parent table
@@ -439,9 +439,9 @@ create index on idxpart (col_keep);
 alter table idxpart attach partition idxpart1 for values from (0) to (1000);
 \d idxpart
 \d idxpart1
-select attrelid::regclass, attname, attnum from pg_attribute
-  where attrelid::regclass::text like 'idxpart%' and attnum > 0
-  order by attrelid::regclass, attnum;
+select attrelid::regclass, attname, attphysnum from pg_attribute
+  where attrelid::regclass::text like 'idxpart%' and attphysnum > 0
+  order by attrelid::regclass, attphysnum;
 drop table idxpart;
 
 --
diff --git a/src/test/regress/sql/inherit.sql b/src/test/regress/sql/inherit.sql
index 195aedb5ff..8075f622b6 100644
--- a/src/test/regress/sql/inherit.sql
+++ b/src/test/regress/sql/inherit.sql
@@ -375,7 +375,7 @@ SELECT a.attrelid::regclass, a.attname, a.attinhcount, e.expected
   FROM (SELECT inhrelid, count(*) AS expected FROM pg_inherits
         WHERE inhparent IN (SELECT inhrelid FROM r) GROUP BY inhrelid) e
   JOIN pg_attribute a ON e.inhrelid = a.attrelid WHERE NOT attislocal
-  ORDER BY a.attrelid::regclass::name, a.attnum;
+  ORDER BY a.attrelid::regclass::name, a.attphysnum;
 
 DROP TABLE inht1, inhs1 CASCADE;
 
diff --git a/src/test/regress/sql/insert.sql b/src/test/regress/sql/insert.sql
index bdcffd0314..5ca1483716 100644
--- a/src/test/regress/sql/insert.sql
+++ b/src/test/regress/sql/insert.sql
@@ -299,8 +299,8 @@ alter table mlparted11 drop a;
 alter table mlparted11 add a int;
 alter table mlparted11 drop a;
 alter table mlparted11 add a int not null;
--- attnum for key attribute 'a' is different in mlparted, mlparted1, and mlparted11
-select attrelid::regclass, attname, attnum
+-- attphysnum for key attribute 'a' is different in mlparted, mlparted1, and mlparted11
+select attrelid::regclass, attname, attphysnum
 from pg_attribute
 where attname = 'a'
  and (attrelid = 'mlparted'::regclass
diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql
index a27a72086e..397f2add63 100644
--- a/src/test/regress/sql/join.sql
+++ b/src/test/regress/sql/join.sql
@@ -1770,8 +1770,8 @@ select uunique1 from
 
 select atts.relid::regclass, s.* from pg_stats s join
     pg_attribute a on s.attname = a.attname and s.tablename =
-    a.attrelid::regclass::text join (select unnest(indkey) attnum,
-    indexrelid from pg_index i) atts on atts.attnum = a.attnum where
+    a.attrelid::regclass::text join (select unnest(indkey) attphysnum,
+    indexrelid from pg_index i) atts on atts.attphysnum = a.attphysnum where
     schemaname != 'pg_catalog';
 
 --
diff --git a/src/test/regress/sql/opr_sanity.sql b/src/test/regress/sql/opr_sanity.sql
index 63fe114fed..5aae345792 100644
--- a/src/test/regress/sql/opr_sanity.sql
+++ b/src/test/regress/sql/opr_sanity.sql
@@ -1353,7 +1353,7 @@ FROM (SELECT indexrelid, indrelid, unnest(indkey) as ikey,
       FROM pg_index) ss,
       pg_attribute a,
       pg_opclass opc
-WHERE a.attrelid = indrelid AND a.attnum = ikey AND opc.oid = iclass AND
+WHERE a.attrelid = indrelid AND a.attphysnum = ikey AND opc.oid = iclass AND
       (NOT binary_coercible(atttypid, opcintype) OR icoll != attcollation);
 
 -- For system catalogs, be even tighter: nearly all indexes should be
@@ -1367,7 +1367,7 @@ FROM (SELECT indexrelid, indrelid, unnest(indkey) as ikey,
       WHERE indrelid < 16384) ss,
       pg_attribute a,
       pg_opclass opc
-WHERE a.attrelid = indrelid AND a.attnum = ikey AND opc.oid = iclass AND
+WHERE a.attrelid = indrelid AND a.attphysnum = ikey AND opc.oid = iclass AND
       (opcintype != atttypid OR icoll != attcollation)
 ORDER BY 1;
 
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index 1149c6a839..4fcb86d67c 100644
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -124,8 +124,8 @@ SELECT 3 AS x, 'Hello', 4 AS y, true AS "dirty\name" \gdesc \g
 create temporary table gexec_test(a int, b text, c date, d float);
 select format('create index on gexec_test(%I)', attname)
 from pg_attribute
-where attrelid = 'gexec_test'::regclass and attnum > 0
-order by attnum
+where attrelid = 'gexec_test'::regclass and attphysnum > 0
+order by attphysnum
 \gexec
 
 -- \gexec should work in FETCH_COUNT mode too
diff --git a/src/test/regress/sql/sanity_check.sql b/src/test/regress/sql/sanity_check.sql
index 7f338d191c..67d6b076b7 100644
--- a/src/test/regress/sql/sanity_check.sql
+++ b/src/test/regress/sql/sanity_check.sql
@@ -11,7 +11,7 @@ SELECT relname, nspname
  WHERE relkind = 'r' and c.oid < 16384
      AND ((nspname ~ '^pg_') IS NOT FALSE)
      AND NOT EXISTS (SELECT 1 FROM pg_index i WHERE indrelid = c.oid
-                     AND indkey[0] = a.attnum AND indnatts = 1
+                     AND indkey[0] = a.attphysnum AND indnatts = 1
                      AND indisunique AND indimmediate);
 
 -- check that relations without storage don't have relfilenode
@@ -34,8 +34,8 @@ WITH check_columns AS (
    SELECT t.oid
     FROM pg_type t JOIN pg_attribute pa ON t.oid = pa.atttypid
     WHERE pa.attrelid = a.attrelid AND
-          pa.attnum > 0 AND pa.attnum < a.attnum
-    ORDER BY pa.attnum) AS coltypes
+          pa.attphysnum > 0 AND pa.attphysnum < a.attphysnum
+    ORDER BY pa.attphysnum) AS coltypes
  FROM pg_attribute a JOIN pg_class c ON c.oid = attrelid
   JOIN pg_namespace n ON c.relnamespace = n.oid
  WHERE attalign = 'd' AND relkind = 'r' AND
diff --git a/src/test/regress/sql/type_sanity.sql b/src/test/regress/sql/type_sanity.sql
index 5edc1f1f6e..fedd8790ac 100644
--- a/src/test/regress/sql/type_sanity.sql
+++ b/src/test/regress/sql/type_sanity.sql
@@ -420,15 +420,15 @@ WHERE pc.relkind IN ('r', 't', 'm') and
 
 SELECT a1.attrelid, a1.attname
 FROM pg_attribute as a1
-WHERE a1.attrelid = 0 OR a1.atttypid = 0 OR a1.attnum = 0 OR
+WHERE a1.attrelid = 0 OR a1.atttypid = 0 OR a1.attphysnum = 0 OR
     a1.attcacheoff != -1 OR a1.attinhcount < 0 OR
     (a1.attinhcount = 0 AND NOT a1.attislocal);
 
--- Cross-check attnum against parent relation
+-- Cross-check attphysnum against parent relation
 
 SELECT a1.attrelid, a1.attname, c1.oid, c1.relname
 FROM pg_attribute AS a1, pg_class AS c1
-WHERE a1.attrelid = c1.oid AND a1.attnum > c1.relnatts;
+WHERE a1.attrelid = c1.oid AND a1.attphysnum > c1.relnatts;
 
 -- Detect missing pg_attribute entries: should have as many non-system
 -- attributes as parent relation expects
@@ -436,7 +436,7 @@ WHERE a1.attrelid = c1.oid AND a1.attnum > c1.relnatts;
 SELECT c1.oid, c1.relname
 FROM pg_class AS c1
 WHERE c1.relnatts != (SELECT count(*) FROM pg_attribute AS a1
-                      WHERE a1.attrelid = c1.oid AND a1.attnum > 0);
+                      WHERE a1.attrelid = c1.oid AND a1.attphysnum > 0);
 
 -- Cross-check against pg_type entry
 -- NOTE: we allow attstorage to be 'plain' even when typstorage is not;
@@ -588,5 +588,5 @@ SELECT oid, typname, typtype, typelem, typarray
     AND NOT EXISTS (SELECT 1
                     FROM pg_attribute a
                     WHERE a.atttypid=t.oid AND
-                          a.attnum > 0 AND
+                          a.attphysnum > 0 AND
                           a.attrelid='tab_core_types'::regclass);
diff --git a/src/tutorial/syscat.source b/src/tutorial/syscat.source
index 6458c32372..9aa7a6e999 100644
--- a/src/tutorial/syscat.source
+++ b/src/tutorial/syscat.source
@@ -57,7 +57,7 @@ SELECT n.nspname AS schema_name,
   WHERE bc.relnamespace = n.oid
      and i.indrelid = bc.oid
      and i.indexrelid = ic.oid
-     and i.indkey[0] = a.attnum
+     and i.indkey[0] = a.attphysnum
      and i.indnatts = 1
      and a.attrelid = bc.oid
   ORDER BY schema_name, class_name, index_name, attname;
@@ -74,7 +74,7 @@ SELECT n.nspname, c.relname, a.attname, format_type(t.oid, null) as typname
     and c.relkind = 'r'     -- no indices
     and n.nspname not like 'pg\_%' -- no catalogs
     and n.nspname != 'information_schema' -- no information_schema
-    and a.attnum > 0        -- no system att's
+    and a.attphysnum > 0        -- no system att's
     and not a.attisdropped   -- no dropped columns
     and a.attrelid = c.oid
     and a.atttypid = t.oid
-- 
2.33.1

