From 4ecebe7a5016cf5acac437fc94267c911f6166d7 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Fri, 1 Mar 2024 10:37:36 +0900 Subject: [PATCH v2 2/2] Allow specifying access method of partitioned tables ..to be inherited by partitions See also: ca4103025dfe26eaaf6a500dec9170fbb176eebc 8586bf7ed8889f39a59dd99b292014b73be85342 ebfe2dbd6b624e2a428e14b7ee9322cc096f63f7 - prevent DROP AM Authors: Justin Pryzby, Soumyadeep Chakraborty --- src/include/catalog/pg_class.h | 4 +- src/include/utils/lsyscache.h | 1 + src/backend/commands/tablecmds.c | 138 +++++++++++++++++++++--- src/backend/utils/cache/lsyscache.c | 22 ++++ src/backend/utils/cache/relcache.c | 7 ++ src/bin/pg_dump/pg_dump.c | 3 +- src/bin/pg_dump/t/002_pg_dump.pl | 35 ++++++ src/test/regress/expected/create_am.out | 108 ++++++++++++++++++- src/test/regress/sql/create_am.sql | 57 +++++++++- doc/src/sgml/catalogs.sgml | 5 +- doc/src/sgml/ref/alter_table.sgml | 8 ++ doc/src/sgml/ref/create_table.sgml | 4 + 12 files changed, 368 insertions(+), 24 deletions(-) diff --git a/src/include/catalog/pg_class.h b/src/include/catalog/pg_class.h index 3b7533e7bb..304241923b 100644 --- a/src/include/catalog/pg_class.h +++ b/src/include/catalog/pg_class.h @@ -219,7 +219,9 @@ MAKE_SYSCACHE(RELNAMENSP, pg_class_relname_nsp_index, 128); /* * Relation kinds with a table access method (rd_tableam). Although sequences * use the heap table AM, they are enough of a special case in most uses that - * they are not included here. + * they are not included here. Likewise, partitioned tables can have an access + * method defined so as their children can inherit it; however, this is handled + * specially outside of this macro. */ #define RELKIND_HAS_TABLE_AM(relkind) \ ((relkind) == RELKIND_RELATION || \ diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h index e4a200b00e..35a8dec2b9 100644 --- a/src/include/utils/lsyscache.h +++ b/src/include/utils/lsyscache.h @@ -139,6 +139,7 @@ extern char get_rel_relkind(Oid relid); extern bool get_rel_relispartition(Oid relid); extern Oid get_rel_tablespace(Oid relid); extern char get_rel_persistence(Oid relid); +extern Oid get_rel_relam(Oid relid); extern Oid get_transform_fromsql(Oid typid, Oid langid, List *trftypes); extern Oid get_transform_tosql(Oid typid, Oid langid, List *trftypes); extern bool get_typisdefined(Oid typid); diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 3b1c2590fd..a234861612 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -592,6 +592,7 @@ static ObjectAddress ATExecClusterOn(Relation rel, const char *indexName, LOCKMODE lockmode); static void ATExecDropCluster(Relation rel, LOCKMODE lockmode); static void ATPrepSetAccessMethod(AlteredTableInfo *tab, Relation rel, const char *amname); +static void ATExecSetAccessMethodNoStorage(Relation rel, Oid newAccessMethod); static bool ATPrepChangePersistence(Relation rel, bool toLogged); static void ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel, const char *tablespacename, LOCKMODE lockmode); @@ -706,7 +707,6 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId, Oid ofTypeId; ObjectAddress address; LOCKMODE parentLockmode; - const char *accessMethod = NULL; Oid accessMethodId = InvalidOid; /* @@ -960,19 +960,28 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId, */ if (stmt->accessMethod != NULL) { - accessMethod = stmt->accessMethod; + accessMethodId = get_table_am_oid(stmt->accessMethod, false); if (partitioned) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("specifying a table access method is not supported on a partitioned table"))); } - else if (RELKIND_HAS_TABLE_AM(relkind)) - accessMethod = default_table_access_method; + else if (stmt->partbound) + { + /* + * For partitions, if no access method is specified, use the AM of the + * parent table. + */ + Assert(list_length(inheritOids) == 1); + accessMethodId = get_rel_relam(linitial_oid(inheritOids)); + } + else + accessMethodId = InvalidOid; - /* look up the access method, verify it is for a table */ - if (accessMethod != NULL) - accessMethodId = get_table_am_oid(accessMethod, false); + /* Still nothing? Use the default */ + if (RELKIND_HAS_TABLE_AM(relkind) && !OidIsValid(accessMethodId)) + accessMethodId = get_table_am_oid(default_table_access_method, false); /* * Create the relation. Inherited defaults and constraints are passed in @@ -5048,12 +5057,6 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd, case AT_SetAccessMethod: /* SET ACCESS METHOD */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_MATVIEW); - /* partitioned tables don't have an access method */ - if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) - ereport(ERROR, - (errcode(ERRCODE_WRONG_OBJECT_TYPE), - errmsg("cannot change access method of a partitioned table"))); - /* check if another access method change was already requested */ if (OidIsValid(tab->newAccessMethod)) ereport(ERROR, @@ -5410,6 +5413,13 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab, break; case AT_SetAccessMethod: /* SET ACCESS METHOD */ /* handled specially in Phase 3 */ + + /* + * Only do this for partitioned tables, for which this is just a + * catalog change. Tables with storage are handled by Phase 3. + */ + if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) + ATExecSetAccessMethodNoStorage(rel, tab->newAccessMethod); break; case AT_SetTableSpace: /* SET TABLESPACE */ @@ -15545,6 +15555,108 @@ ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode) list_free(reltoastidxids); } +/* + * Special handling of ALTER TABLE SET ACCESS METHOD for relations with no + * storage that have an interest in preserving AM. + * + * Since these have no storage, setting the access method is a catalog only + * operation. + */ +static void +ATExecSetAccessMethodNoStorage(Relation rel, Oid newAccessMethodId) +{ + Relation pg_class; + Oid oldAccessMethodId; + HeapTuple tuple; + Form_pg_class rd_rel; + Oid reloid = RelationGetRelid(rel); + Oid defaultAccessMethodId; + + if (!OidIsValid(newAccessMethodId)) + { + /* if the access method is unchanged, leave */ + return; + } + + /* + * Shouldn't be called on relations having storage; these are processed in + * phase 3. + */ + Assert(!RELKIND_HAS_STORAGE(rel->rd_rel->relkind)); + defaultAccessMethodId = get_table_am_oid(default_table_access_method, false); + + /* Get a modifiable copy of the relation's pg_class row. */ + pg_class = table_open(RelationRelationId, RowExclusiveLock); + + tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(reloid)); + if (!HeapTupleIsValid(tuple)) + elog(ERROR, "cache lookup failed for relation %u", reloid); + rd_rel = (Form_pg_class) GETSTRUCT(tuple); + + /* Update the pg_class row. */ + oldAccessMethodId = rd_rel->relam; + rd_rel->relam = (newAccessMethodId == defaultAccessMethodId) ? + InvalidOid : newAccessMethodId; + + /* Leave if no update required */ + if (rd_rel->relam == oldAccessMethodId) + { + heap_freetuple(tuple); + table_close(pg_class, RowExclusiveLock); + return; + } + + CatalogTupleUpdate(pg_class, &tuple->t_self, tuple); + + /* + * Update the dependency on the new access method. No dependency is added + * if the access method is InvalidOid. + */ + if (!OidIsValid(oldAccessMethodId) && OidIsValid(newAccessMethodId)) + { + ObjectAddress relobj, + referenced; + + /* + * New access method is defined and there was no dependency + * previously, so record a new one. + */ + ObjectAddressSet(relobj, RelationRelationId, reloid); + ObjectAddressSet(referenced, AccessMethodRelationId, newAccessMethodId); + recordDependencyOn(&relobj, &referenced, DEPENDENCY_NORMAL); + } + else if (OidIsValid(oldAccessMethodId) && + newAccessMethodId == defaultAccessMethodId) + { + /* + * There was an access method defined, and no new one, so just remove + * the existing dependency. + */ + deleteDependencyRecordsForClass(RelationRelationId, reloid, + AccessMethodRelationId, + DEPENDENCY_NORMAL); + } + else + { + Assert(OidIsValid(oldAccessMethodId) && + newAccessMethodId != defaultAccessMethodId); + + /* Both are valid, so update the dependency */ + changeDependencyFor(RelationRelationId, reloid, AccessMethodRelationId, + oldAccessMethodId, newAccessMethodId); + } + + CommandCounterIncrement(); + + InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0); + + heap_freetuple(tuple); + table_close(pg_class, RowExclusiveLock); + + /* Make sure the relam change is visible */ + CommandCounterIncrement(); +} + /* * Special handling of ALTER TABLE SET TABLESPACE for relations with no * storage that have an interest in preserving tablespace. diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c index f730aa26c4..2ea249e90c 100644 --- a/src/backend/utils/cache/lsyscache.c +++ b/src/backend/utils/cache/lsyscache.c @@ -2068,6 +2068,28 @@ get_rel_persistence(Oid relid) return result; } +/* + * get_rel_relam + * + * Returns the relam associated with a given relation. + */ +Oid +get_rel_relam(Oid relid) +{ + HeapTuple tp; + Form_pg_class reltup; + Oid result; + + tp = SearchSysCache1(RELOID, ObjectIdGetDatum(relid)); + if (!HeapTupleIsValid(tp)) + elog(ERROR, "cache lookup failed for relation %u", relid); + reltup = (Form_pg_class) GETSTRUCT(tp); + result = reltup->relam; + ReleaseSysCache(tp); + + return result; +} + /* ---------- TRANSFORM CACHE ---------- */ diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c index 50acae4529..e80f156912 100644 --- a/src/backend/utils/cache/relcache.c +++ b/src/backend/utils/cache/relcache.c @@ -1210,6 +1210,13 @@ retry: else if (RELKIND_HAS_TABLE_AM(relation->rd_rel->relkind) || relation->rd_rel->relkind == RELKIND_SEQUENCE) RelationInitTableAccessMethod(relation); + else if (relation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) + { + /* + * Do nothing: access methods is a setting that partitions can + * inherit. + */ + } else Assert(relation->rd_rel->relam == InvalidOid); diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c index 2225a12718..91a7031b05 100644 --- a/src/bin/pg_dump/pg_dump.c +++ b/src/bin/pg_dump/pg_dump.c @@ -16610,7 +16610,8 @@ dumpTableSchema(Archive *fout, const TableInfo *tbinfo) if (RELKIND_HAS_TABLESPACE(tbinfo->relkind)) tablespace = tbinfo->reltablespace; - if (RELKIND_HAS_TABLE_AM(tbinfo->relkind)) + if (RELKIND_HAS_TABLE_AM(tbinfo->relkind) || + tbinfo->relkind == RELKIND_PARTITIONED_TABLE) tableam = tbinfo->amname; ArchiveEntry(fout, tbinfo->dobj.catId, tbinfo->dobj.dumpId, diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl index 00b5092713..dfee1982f4 100644 --- a/src/bin/pg_dump/t/002_pg_dump.pl +++ b/src/bin/pg_dump/t/002_pg_dump.pl @@ -4587,6 +4587,41 @@ my %tests = ( no_table_access_method => 1, only_dump_measurement => 1, }, + }, + + # CREATE TABLE with partitioned table and various AMs. One + # partition uses the same default as the parent, and a second + # uses its own AM. + 'CREATE TABLE regress_pg_dump_table_part' => { + create_order => 19, + create_sql => ' + CREATE TABLE dump_test.regress_pg_dump_table_am_parent (id int) PARTITION BY LIST (id); + ALTER TABLE dump_test.regress_pg_dump_table_am_parent SET ACCESS METHOD regress_table_am; + CREATE TABLE dump_test.regress_pg_dump_table_am_child_1 + PARTITION OF dump_test.regress_pg_dump_table_am_parent FOR VALUES IN (1) USING heap; + CREATE TABLE dump_test.regress_pg_dump_table_am_child_2 + PARTITION OF dump_test.regress_pg_dump_table_am_parent FOR VALUES IN (2);', + regexp => qr/^ + \QSET default_table_access_method = regress_table_am;\E + (\n(?!SET[^;]+;)[^\n]*)* + \n\QCREATE TABLE dump_test.regress_pg_dump_table_am_parent (\E + (.*\n)* + \QSET default_table_access_method = heap;\E + (\n(?!SET[^;]+;)[^\n]*)* + \n\QCREATE TABLE dump_test.regress_pg_dump_table_am_child_1 (\E + (.*\n)* + \QSET default_table_access_method = regress_table_am;\E + (\n(?!SET[^;]+;)[^\n]*)* + \n\QCREATE TABLE dump_test.regress_pg_dump_table_am_child_2 (\E + (.*\n)*/xm, + like => { + %full_runs, %dump_test_schema_runs, section_pre_data => 1, + }, + unlike => { + exclude_dump_test_schema => 1, + no_table_access_method => 1, + only_dump_measurement => 1, + }, }); ######################################### diff --git a/src/test/regress/expected/create_am.out b/src/test/regress/expected/create_am.out index e843d39ee7..f990887752 100644 --- a/src/test/regress/expected/create_am.out +++ b/src/test/regress/expected/create_am.out @@ -334,12 +334,112 @@ ALTER MATERIALIZED VIEW heapmv SET ACCESS METHOD heap, SET ACCESS METHOD heap2; ERROR: cannot have multiple SET ACCESS METHOD subcommands DROP MATERIALIZED VIEW heapmv; DROP TABLE heaptable; --- No support for partitioned tables. -CREATE TABLE am_partitioned(x INT, y INT) - PARTITION BY hash (x); +-- Partition hierarchies with access methods +BEGIN; +SET LOCAL default_table_access_method = 'heap'; +CREATE TABLE am_partitioned(x INT, y INT) PARTITION BY hash (x); +-- pg_class.relam is 0, no dependency recorded between the AM and the +-- partitioned table. +SELECT relam FROM pg_class WHERE relname = 'am_partitioned'; + relam +------- + 0 +(1 row) + +SELECT pg_describe_object(classid, objid, objsubid) AS obj, + pg_describe_object(refclassid, refobjid, refobjsubid) as refobj + FROM pg_depend, pg_am + WHERE pg_depend.refclassid = 'pg_am'::regclass + AND pg_am.oid = pg_depend.refobjid + AND pg_depend.objid = 'am_partitioned'::regclass; + obj | refobj +-----+-------- +(0 rows) + +-- New default is set, with dependency added. ALTER TABLE am_partitioned SET ACCESS METHOD heap2; -ERROR: cannot change access method of a partitioned table +SELECT a.amname FROM pg_class c, pg_am a + WHERE c.relname = 'am_partitioned' AND a.oid = c.relam; + amname +-------- + heap2 +(1 row) + +SELECT pg_describe_object(classid, objid, objsubid) AS obj, + pg_describe_object(refclassid, refobjid, refobjsubid) as refobj + FROM pg_depend, pg_am + WHERE pg_depend.refclassid = 'pg_am'::regclass + AND pg_am.oid = pg_depend.refobjid + AND pg_depend.objid = 'am_partitioned'::regclass; + obj | refobj +----------------------+--------------------- + table am_partitioned | access method heap2 +(1 row) + +-- Default is set, with dependency updated. +SET LOCAL default_table_access_method = 'heap2'; +ALTER TABLE am_partitioned SET ACCESS METHOD heap; +SELECT a.amname FROM pg_class c, pg_am a + WHERE c.relname = 'am_partitioned' AND a.oid = c.relam; + amname +-------- + heap +(1 row) + +-- Dependency pinned, hence removed. +SELECT pg_describe_object(classid, objid, objsubid) AS obj, + pg_describe_object(refclassid, refobjid, refobjsubid) as refobj + FROM pg_depend, pg_am + WHERE pg_depend.refclassid = 'pg_am'::regclass + AND pg_am.oid = pg_depend.refobjid + AND pg_depend.objid = 'am_partitioned'::regclass; + obj | refobj +-----+-------- +(0 rows) + +-- Reset to default +ALTER TABLE am_partitioned SET ACCESS METHOD heap2; +SELECT relam FROM pg_class WHERE relname = 'am_partitioned'; + relam +------- + 0 +(1 row) + +-- Upon ALTER TABLE SET ACCESS METHOD on a partitioned table, new partitions +-- will inherit the AM set. Existing partitioned are unchanged +SELECT relam FROM pg_class WHERE relname = 'am_partitioned'; + relam +------- + 0 +(1 row) + +SET LOCAL default_table_access_method = 'heap'; +CREATE TABLE am_partitioned_1 PARTITION OF am_partitioned FOR VALUES WITH (MODULUS 4,REMAINDER 0); +SET LOCAL default_table_access_method = 'heap2'; +CREATE TABLE am_partitioned_2 PARTITION OF am_partitioned FOR VALUES WITH (MODULUS 4,REMAINDER 1); +SET LOCAL default_table_access_method = 'heap'; +ALTER TABLE am_partitioned SET ACCESS METHOD heap2; +CREATE TABLE am_partitioned_3 PARTITION OF am_partitioned FOR VALUES WITH (MODULUS 4,REMAINDER 2); +ALTER TABLE am_partitioned SET ACCESS METHOD DEFAULT; +SELECT relam FROM pg_class WHERE relname = 'am_partitioned'; + relam +------- + 0 +(1 row) + +CREATE TABLE am_partitioned_4 PARTITION OF am_partitioned FOR VALUES WITH (MODULUS 4,REMAINDER 3); +SELECT c.relname, a.amname FROM pg_class c, pg_am a + WHERE c.relam = a.oid AND c.relname LIKE 'am_partitioned%' ORDER BY 1; + relname | amname +------------------+-------- + am_partitioned_1 | heap + am_partitioned_2 | heap2 + am_partitioned_3 | heap2 + am_partitioned_4 | heap +(4 rows) + DROP TABLE am_partitioned; +COMMIT; -- Second, create objects in the new AM by changing the default AM BEGIN; SET LOCAL default_table_access_method = 'heap2'; diff --git a/src/test/regress/sql/create_am.sql b/src/test/regress/sql/create_am.sql index f752bf1678..db6490e6c3 100644 --- a/src/test/regress/sql/create_am.sql +++ b/src/test/regress/sql/create_am.sql @@ -212,11 +212,62 @@ ALTER TABLE heaptable SET ACCESS METHOD heap, SET ACCESS METHOD heap2; ALTER MATERIALIZED VIEW heapmv SET ACCESS METHOD heap, SET ACCESS METHOD heap2; DROP MATERIALIZED VIEW heapmv; DROP TABLE heaptable; --- No support for partitioned tables. -CREATE TABLE am_partitioned(x INT, y INT) - PARTITION BY hash (x); + +-- Partition hierarchies with access methods +BEGIN; +SET LOCAL default_table_access_method = 'heap'; +CREATE TABLE am_partitioned(x INT, y INT) PARTITION BY hash (x); +-- pg_class.relam is 0, no dependency recorded between the AM and the +-- partitioned table. +SELECT relam FROM pg_class WHERE relname = 'am_partitioned'; +SELECT pg_describe_object(classid, objid, objsubid) AS obj, + pg_describe_object(refclassid, refobjid, refobjsubid) as refobj + FROM pg_depend, pg_am + WHERE pg_depend.refclassid = 'pg_am'::regclass + AND pg_am.oid = pg_depend.refobjid + AND pg_depend.objid = 'am_partitioned'::regclass; +-- New default is set, with dependency added. ALTER TABLE am_partitioned SET ACCESS METHOD heap2; +SELECT a.amname FROM pg_class c, pg_am a + WHERE c.relname = 'am_partitioned' AND a.oid = c.relam; +SELECT pg_describe_object(classid, objid, objsubid) AS obj, + pg_describe_object(refclassid, refobjid, refobjsubid) as refobj + FROM pg_depend, pg_am + WHERE pg_depend.refclassid = 'pg_am'::regclass + AND pg_am.oid = pg_depend.refobjid + AND pg_depend.objid = 'am_partitioned'::regclass; +-- Default is set, with dependency updated. +SET LOCAL default_table_access_method = 'heap2'; +ALTER TABLE am_partitioned SET ACCESS METHOD heap; +SELECT a.amname FROM pg_class c, pg_am a + WHERE c.relname = 'am_partitioned' AND a.oid = c.relam; +-- Dependency pinned, hence removed. +SELECT pg_describe_object(classid, objid, objsubid) AS obj, + pg_describe_object(refclassid, refobjid, refobjsubid) as refobj + FROM pg_depend, pg_am + WHERE pg_depend.refclassid = 'pg_am'::regclass + AND pg_am.oid = pg_depend.refobjid + AND pg_depend.objid = 'am_partitioned'::regclass; +-- Reset to default +ALTER TABLE am_partitioned SET ACCESS METHOD heap2; +SELECT relam FROM pg_class WHERE relname = 'am_partitioned'; +-- Upon ALTER TABLE SET ACCESS METHOD on a partitioned table, new partitions +-- will inherit the AM set. Existing partitioned are unchanged +SELECT relam FROM pg_class WHERE relname = 'am_partitioned'; +SET LOCAL default_table_access_method = 'heap'; +CREATE TABLE am_partitioned_1 PARTITION OF am_partitioned FOR VALUES WITH (MODULUS 4,REMAINDER 0); +SET LOCAL default_table_access_method = 'heap2'; +CREATE TABLE am_partitioned_2 PARTITION OF am_partitioned FOR VALUES WITH (MODULUS 4,REMAINDER 1); +SET LOCAL default_table_access_method = 'heap'; +ALTER TABLE am_partitioned SET ACCESS METHOD heap2; +CREATE TABLE am_partitioned_3 PARTITION OF am_partitioned FOR VALUES WITH (MODULUS 4,REMAINDER 2); +ALTER TABLE am_partitioned SET ACCESS METHOD DEFAULT; +SELECT relam FROM pg_class WHERE relname = 'am_partitioned'; +CREATE TABLE am_partitioned_4 PARTITION OF am_partitioned FOR VALUES WITH (MODULUS 4,REMAINDER 3); +SELECT c.relname, a.amname FROM pg_class c, pg_am a + WHERE c.relam = a.oid AND c.relname LIKE 'am_partitioned%' ORDER BY 1; DROP TABLE am_partitioned; +COMMIT; -- Second, create objects in the new AM by changing the default AM BEGIN; diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml index 880f717b10..359d03b7f1 100644 --- a/doc/src/sgml/catalogs.sgml +++ b/doc/src/sgml/catalogs.sgml @@ -1989,8 +1989,9 @@ SCRAM-SHA-256$<iteration count>:&l If this is a table or an index, the access method used (heap, - B-tree, hash, etc.); otherwise zero (zero occurs for sequences, - as well as relations without storage, such as views) + B-tree, hash, etc.); otherwise zero. Zero occurs for sequences, + as well as relations without storage, such as views. Partitioned + tables may use a non-zero value. diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml index 96e3d77605..fbbab72784 100644 --- a/doc/src/sgml/ref/alter_table.sgml +++ b/doc/src/sgml/ref/alter_table.sgml @@ -737,6 +737,14 @@ WITH ( MODULUS numeric_literal, REM DEFAULT changes the access method of the table to . + + When applied to a partitioned table, there is no data to rewrite, but any + partitions created afterwards will use that access method unless + overridden by a USING clause. If the value + specified is the same as default_table_access_method + the partitioned table is switched to rely on the default that is set at + the time when new partitions are created, instead. + diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml index 4cbaaccaf7..b79081a5ec 100644 --- a/doc/src/sgml/ref/create_table.sgml +++ b/doc/src/sgml/ref/create_table.sgml @@ -1330,6 +1330,10 @@ WITH ( MODULUS numeric_literal, REM method is chosen for the new table. See for more information. + + When creating a partition, the table access method is the access method + of its partitioned table, if set. + -- 2.43.0