From a5724c200748993ea6e1e22948961a5c0f821f9d Mon Sep 17 00:00:00 2001 From: Manni Wood Date: Tue, 28 Oct 2025 17:36:10 -0500 Subject: [PATCH v1] Adds pg_get_tablespace_ddl function Currently, there exist ways of "wholesale" dumping the DDL for an entire database or even cluster; this function will ideally be part of a suite of similar "retail" functions for dumping the DDL of various database objects. --- doc/src/sgml/func/func-info.sgml | 45 +++++++++ src/backend/utils/adt/ruleutils.c | 118 +++++++++++++++++++++++ src/include/catalog/pg_proc.dat | 3 + src/test/regress/expected/tablespace.out | 59 ++++++++++++ src/test/regress/sql/tablespace.sql | 41 ++++++++ 5 files changed, 266 insertions(+) diff --git a/doc/src/sgml/func/func-info.sgml b/doc/src/sgml/func/func-info.sgml index c393832d94c..79ef14c6b2f 100644 --- a/doc/src/sgml/func/func-info.sgml +++ b/doc/src/sgml/func/func-info.sgml @@ -3797,4 +3797,49 @@ acl | {postgres=arwdDxtm/postgres,foo=r/postgres} + + Get Object DDL Functions + + + The functions shown in + print the DDL statements for various database objects. + (This is a decompiled reconstruction, not the original text + of the command.) + + + + Get Object DDL Functions + + + + + Function + + + Description + + + + + + + + + pg_get_tablespace_ddl + + pg_get_tablespace_ddl + ( tablespace name ) + text + + + Reconstructs the creating command for a tablespace. + The result is a complete CREATE TABLESPACE statement. + + + + +
+ + + diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 79ec136231b..6b8aedc2115 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -22,6 +22,7 @@ #include "access/amapi.h" #include "access/htup_details.h" #include "access/relation.h" +#include "access/reloptions.h" #include "access/table.h" #include "catalog/pg_aggregate.h" #include "catalog/pg_am.h" @@ -35,6 +36,7 @@ #include "catalog/pg_partitioned_table.h" #include "catalog/pg_proc.h" #include "catalog/pg_statistic_ext.h" +#include "catalog/pg_tablespace.h" #include "catalog/pg_trigger.h" #include "catalog/pg_type.h" #include "commands/defrem.h" @@ -67,6 +69,7 @@ #include "utils/rel.h" #include "utils/ruleutils.h" #include "utils/snapmgr.h" +#include "utils/spccache.h" #include "utils/syscache.h" #include "utils/typcache.h" #include "utils/varlena.h" @@ -13738,3 +13741,118 @@ get_range_partbound_string(List *bound_datums) return buf->data; } + +/* + * pg_get_tablespace_ddl - Get CREATE TABLESPACE statement for a tablespace + */ +Datum +pg_get_tablespace_ddl(PG_FUNCTION_ARGS) +{ + Name tspname = PG_GETARG_NAME(0); + char *path; + char *spcowner; + bool isNull; + Oid tspaceoid; + Oid tspowneroid; + Datum datumLocation; + Datum datum; + HeapTuple tuple; + StringInfoData buf; + TableSpaceOpts *opts = NULL; + Form_pg_tablespace tspForm; + + /* Get the OID of the tablespace; we need it to find the tablespace */ + tspaceoid = get_tablespace_oid(NameStr(*tspname), false); + + /* Look up the tablespace in pg_tablespace */ + tuple = SearchSysCache1(TABLESPACEOID, ObjectIdGetDatum(tspaceoid)); + + Assert(HeapTupleIsValid(tuple)); + + initStringInfo(&buf); + + /* Start building the CREATE TABLESPACE statement */ + appendStringInfo(&buf, "CREATE TABLESPACE %s", + quote_identifier(NameStr(*tspname))); + + /* Get the OID of the owner of the tablespace name */ + tspForm = (Form_pg_tablespace) GETSTRUCT(tuple); + tspowneroid = tspForm->spcowner; + + /* Add OWNER clause, if the owner is not the current user */ + if (GetUserId() != tspowneroid) + { + /* Get the owner name */ + spcowner = GetUserNameFromId(tspowneroid, false); + + appendStringInfo(&buf, " OWNER %s", + quote_identifier(spcowner)); + } + + /* Find tablespace directory path */ + datumLocation = DirectFunctionCall1(pg_tablespace_location, tspaceoid); + path = text_to_cstring(DatumGetTextP(datumLocation)); + /* Add directory LOCATION (path), if it exists */ + if (path[0] != '\0') + { + /* + * Special case: if the tablespace was created with GUC + * "allow_in_place_tablespaces = true" and "LOCATION ''", path will + * begin with "pg_tblspc/". In that case, show "LOCATION ''" as the + * user originally specified. + */ + if (strncmp(PG_TBLSPC_DIR_SLASH, path, strlen(PG_TBLSPC_DIR_SLASH)) == 0) + appendStringInfoString(&buf, " LOCATION ''"); + else + appendStringInfo(&buf, " LOCATION '%s'", path); + } + + /* Get tablespace's options datum from the tuple */ + datum = SysCacheGetAttr(TABLESPACEOID, + tuple, + Anum_pg_tablespace_spcoptions, + &isNull); + + if (!isNull) + { + bytea *bytea_opts = tablespace_reloptions(datum, false); + + opts = (TableSpaceOpts *) palloc0(VARSIZE(bytea_opts)); + memcpy(opts, bytea_opts, VARSIZE(bytea_opts)); + + /* Add the valid options in WITH clause */ + appendStringInfoString(&buf, " WITH ("); + + if (opts->random_page_cost > 0) + appendStringInfo(&buf, "random_page_cost = %g, ", + opts->random_page_cost); + + if (opts->seq_page_cost > 0) + appendStringInfo(&buf, "seq_page_cost = %g, ", + opts->seq_page_cost); + + if (opts->effective_io_concurrency > 0) + appendStringInfo(&buf, "effective_io_concurrency = %d, ", + opts->effective_io_concurrency); + + if (opts->maintenance_io_concurrency > 0) + appendStringInfo(&buf, "maintenance_io_concurrency = %d, ", + opts->maintenance_io_concurrency); + + /* buf ends up with unwanted trailing comma and space; remove them */ + buf.len -= 2; + buf.data[buf.len] = '\0'; /* Null-terminate the modified string */ + + /* Free the opts now */ + pfree(opts); + + appendStringInfoChar(&buf, ')'); + } + + ReleaseSysCache(tuple); + + /* Finally add semicolon to the statement */ + appendStringInfoChar(&buf, ';'); + + PG_RETURN_TEXT_P(string_to_text(buf.data)); +} diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 9121a382f76..022c3493542 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -8515,6 +8515,9 @@ { oid => '2508', descr => 'constraint description with pretty-print option', proname => 'pg_get_constraintdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid bool', prosrc => 'pg_get_constraintdef_ext' }, +{ oid => '8758', descr => 'get CREATE statement for tablespace', + proname => 'pg_get_tablespace_ddl', prorettype => 'text', + proargtypes => 'name', prosrc => 'pg_get_tablespace_ddl' }, { oid => '2509', descr => 'deparse an encoded expression with pretty-print option', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out index a90e39e5738..8a1c678b1db 100644 --- a/src/test/regress/expected/tablespace.out +++ b/src/test/regress/expected/tablespace.out @@ -971,3 +971,62 @@ drop cascades to materialized view testschema.amv drop cascades to table testschema.tablespace_acl DROP ROLE regress_tablespace_user1; DROP ROLE regress_tablespace_user2; +-- Test pg_get_tablespace_ddl() by creating tablespaces with various +-- configurations and checking the DDL. +SET allow_in_place_tablespaces = true; +-- create a tablespace using no options +CREATE TABLESPACE regress_noopt_tblsp LOCATION ''; -- ok +-- see that the tablespace ddl is correctly returned +SELECT pg_get_tablespace_ddl('regress_noopt_tblsp'); + pg_get_tablespace_ddl +---------------------------------------------------- + CREATE TABLESPACE regress_noopt_tblsp LOCATION ''; +(1 row) + +DROP TABLESPACE regress_noopt_tblsp; +-- create a tablespace using one option +CREATE TABLESPACE regress_oneopt_tblsp LOCATION '' WITH (random_page_cost = 3.0); -- ok +-- see that the tablespace ddl is correctly returned +SELECT pg_get_tablespace_ddl('regress_oneopt_tblsp'); + pg_get_tablespace_ddl +--------------------------------------------------------------------------------- + CREATE TABLESPACE regress_oneopt_tblsp LOCATION '' WITH (random_page_cost = 3); +(1 row) + +DROP TABLESPACE regress_oneopt_tblsp; +-- create tablespace owned by a particular user +CREATE USER regress_user; +CREATE TABLESPACE regress_owner_tblsp OWNER regress_user LOCATION '' WITH (random_page_cost = 3.0); -- ok +-- see that the tablespace ddl is correctly returned +SELECT pg_get_tablespace_ddl('regress_owner_tblsp'); + pg_get_tablespace_ddl +--------------------------------------------------------------------------------------------------- + CREATE TABLESPACE regress_owner_tblsp OWNER regress_user LOCATION '' WITH (random_page_cost = 3); +(1 row) + +DROP TABLESPACE regress_owner_tblsp; +DROP USER regress_user; +-- create a tablespace using all the options +CREATE TABLESPACE regress_allopt_tblsp LOCATION '' WITH (seq_page_cost = 1.5, random_page_cost = 1.6, effective_io_concurrency = 17, maintenance_io_concurrency = 18); -- ok +-- see that the tablespace ddl is correctly returned +SELECT pg_get_tablespace_ddl('regress_allopt_tblsp'); + pg_get_tablespace_ddl +------------------------------------------------------------------------------------------------------------------------------------------------------------------------ + CREATE TABLESPACE regress_allopt_tblsp LOCATION '' WITH (random_page_cost = 1.6, seq_page_cost = 1.5, effective_io_concurrency = 17, maintenance_io_concurrency = 18); +(1 row) + +DROP TABLESPACE regress_allopt_tblsp; +-- see the pg_get_tablespace_ddl error for a dropped 'regress_allopt_tblsp' +-- tablespace name +SELECT pg_get_tablespace_ddl('regress_allopt_tblsp'); +ERROR: tablespace "regress_allopt_tblsp" does not exist +-- see the pg_get_tablespace_ddl error for an empty input +SELECT pg_get_tablespace_ddl(''); +ERROR: tablespace "" does not exist +-- see the pg_get_tablespace_ddl output for a NULL input +SELECT pg_get_tablespace_ddl(NULL); + pg_get_tablespace_ddl +----------------------- + +(1 row) + diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql index dfe3db096e2..2a478558c25 100644 --- a/src/test/regress/sql/tablespace.sql +++ b/src/test/regress/sql/tablespace.sql @@ -437,3 +437,44 @@ DROP SCHEMA testschema CASCADE; DROP ROLE regress_tablespace_user1; DROP ROLE regress_tablespace_user2; + +-- Test pg_get_tablespace_ddl() by creating tablespaces with various +-- configurations and checking the DDL. + +SET allow_in_place_tablespaces = true; + +-- create a tablespace using no options +CREATE TABLESPACE regress_noopt_tblsp LOCATION ''; -- ok +-- see that the tablespace ddl is correctly returned +SELECT pg_get_tablespace_ddl('regress_noopt_tblsp'); +DROP TABLESPACE regress_noopt_tblsp; + +-- create a tablespace using one option +CREATE TABLESPACE regress_oneopt_tblsp LOCATION '' WITH (random_page_cost = 3.0); -- ok +-- see that the tablespace ddl is correctly returned +SELECT pg_get_tablespace_ddl('regress_oneopt_tblsp'); +DROP TABLESPACE regress_oneopt_tblsp; + +-- create tablespace owned by a particular user +CREATE USER regress_user; +CREATE TABLESPACE regress_owner_tblsp OWNER regress_user LOCATION '' WITH (random_page_cost = 3.0); -- ok +-- see that the tablespace ddl is correctly returned +SELECT pg_get_tablespace_ddl('regress_owner_tblsp'); +DROP TABLESPACE regress_owner_tblsp; +DROP USER regress_user; + +-- create a tablespace using all the options +CREATE TABLESPACE regress_allopt_tblsp LOCATION '' WITH (seq_page_cost = 1.5, random_page_cost = 1.6, effective_io_concurrency = 17, maintenance_io_concurrency = 18); -- ok +-- see that the tablespace ddl is correctly returned +SELECT pg_get_tablespace_ddl('regress_allopt_tblsp'); +DROP TABLESPACE regress_allopt_tblsp; + +-- see the pg_get_tablespace_ddl error for a dropped 'regress_allopt_tblsp' +-- tablespace name +SELECT pg_get_tablespace_ddl('regress_allopt_tblsp'); + +-- see the pg_get_tablespace_ddl error for an empty input +SELECT pg_get_tablespace_ddl(''); + +-- see the pg_get_tablespace_ddl output for a NULL input +SELECT pg_get_tablespace_ddl(NULL); -- 2.43.0