From 29e92da55e817c7938cf0be5bdda4bc2d420c7ca Mon Sep 17 00:00:00 2001 From: Manni Wood Date: Fri, 7 Nov 2025 15:59:14 -0600 Subject: [PATCH v8 2/2] Adds pg_get_tablespace_ddl function MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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. Authors: Manni Wood and Nishant Sharma Reviewers: Vaibhav Dalvi, Ian Barwick, Jim Jones, Álvaro Herrera Discussion: https://www.postgresql.org/message-id/flat/CAKWEB6rmnmGKUA87Zmq-s=b3Scsnj02C0kObQjnbL2ajfPWGEw@mail.gmail.com --- doc/src/sgml/func/func-info.sgml | 45 +++++++ src/backend/utils/adt/ruleutils.c | 153 +++++++++++++++++++++++ src/include/catalog/pg_proc.dat | 6 + src/test/regress/expected/tablespace.out | 69 ++++++++++ src/test/regress/sql/tablespace.sql | 47 +++++++ 5 files changed, 320 insertions(+) diff --git a/doc/src/sgml/func/func-info.sgml b/doc/src/sgml/func/func-info.sgml index d4508114a48..74ca0ed1066 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 c8023e83f4b..31ddd2ea49a 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -36,6 +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" @@ -13744,3 +13745,155 @@ get_range_partbound_string(List *bound_datums) return buf.data; } + +/* + * build_tablespace_ddl_string - Build CREATE TABLESPACE statement for + * a tablespace from its OID. This is internal version which helps + * pg_get_tablespace_ddl_name() and pg_get_tablespace_ddl_oid(). + */ +char * +build_tablespace_ddl_string(const Oid tspaceoid) +{ + char *path; + char *spcowner; + bool isNull; + Oid tspowneroid; + Datum datum; + HeapTuple tuple; + StringInfoData buf; + Form_pg_tablespace tspForm; + + /* Look up the tablespace in pg_tablespace */ + tuple = SearchSysCache1(TABLESPACEOID, ObjectIdGetDatum(tspaceoid)); + + /* Confirm if tablespace OID was valid */ + if (!HeapTupleIsValid(tuple)) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("tablespace with oid %d does not exist", + tspaceoid))); + + /* Get tablespace's details from its tuple */ + tspForm = (Form_pg_tablespace) GETSTRUCT(tuple); + + initStringInfo(&buf); + + /* Start building the CREATE TABLESPACE statement */ + appendStringInfo(&buf, "CREATE TABLESPACE %s", + quote_identifier(NameStr(tspForm->spcname))); + + /* Get the OID of the owner of the tablespace name */ + 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)); + pfree(spcowner); + } + + /* Find tablespace directory path */ + path = get_tablespace_loc_string(tspaceoid); + + /* 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); + } + /* Done with path */ + pfree(path); + + /* Get tablespace's options datum from the tuple */ + datum = SysCacheGetAttr(TABLESPACEOID, + tuple, + Anum_pg_tablespace_spcoptions, + &isNull); + + if (!isNull) + { + ArrayType *optarray; + Datum *optdatums; + int optcount; + int i; + + optarray = DatumGetArrayTypeP(datum); + + deconstruct_array_builtin(optarray, TEXTOID, + &optdatums, NULL, &optcount); + + Assert(optcount); + + /* Start WITH clause */ + appendStringInfoString(&buf, " WITH ("); + + for (i = 0; i < (optcount - 1); i++) /* Skipping last option */ + { + /* Add the options in WITH clause */ + appendStringInfoString(&buf, TextDatumGetCString(optdatums[i])); + appendStringInfoString(&buf, ", "); + } + + /* Adding the last remaining option */ + appendStringInfoString(&buf, TextDatumGetCString(optdatums[i])); + /* Closing WITH clause */ + appendStringInfoChar(&buf, ')'); + /* Cleanup the datums found */ + pfree(optdatums); + } + + ReleaseSysCache(tuple); + + /* Finally add semicolon to the statement */ + appendStringInfoChar(&buf, ';'); + + return buf.data; +} + +/* + * pg_get_tablespace_ddl_name - Get CREATE TABLESPACE statement for a + * tablespace. This takes name as parameter for pg_get_tablespace_ddl(). + */ +Datum +pg_get_tablespace_ddl_name(PG_FUNCTION_ARGS) +{ + Name tspname = PG_GETARG_NAME(0); + Oid tspaceoid; + char *ddl_stmt; + + /* Get the OID of the tablespace from its name */ + tspaceoid = get_tablespace_oid(NameStr(*tspname), false); + + /* Get the CREATE TABLESPACE DDL statement from its OID */ + ddl_stmt = build_tablespace_ddl_string(tspaceoid); + + PG_RETURN_TEXT_P(string_to_text(ddl_stmt)); +} + +/* + * pg_get_tablespace_ddl_oid - Get CREATE TABLESPACE statement for a + * tablespace. This takes oid as parameter for pg_get_tablespace_ddl(). + */ +Datum +pg_get_tablespace_ddl_oid(PG_FUNCTION_ARGS) +{ + Oid tspaceoid = PG_GETARG_OID(0); + char *ddl_stmt; + + /* Get the CREATE TABLESPACE DDL statement from its OID */ + ddl_stmt = build_tablespace_ddl_string(tspaceoid); + + PG_RETURN_TEXT_P(string_to_text(ddl_stmt)); +} diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 5cf9e12fcb9..0fcd0f4fa8f 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -8515,6 +8515,12 @@ { 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_name' }, +{ oid => '8759', descr => 'get CREATE statement for tablespace', + proname => 'pg_get_tablespace_ddl', prorettype => 'text', + proargtypes => 'oid', prosrc => 'pg_get_tablespace_ddl_oid' }, { 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..6b77e3323d1 100644 --- a/src/test/regress/expected/tablespace.out +++ b/src/test/regress/expected/tablespace.out @@ -971,3 +971,72 @@ 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 with a space in the name +CREATE TABLESPACE "regress_ tblsp" LOCATION ''; -- ok +-- see that the tablespace ddl is correctly returned +SELECT pg_get_tablespace_ddl('regress_ tblsp'); + pg_get_tablespace_ddl +------------------------------------------------- + CREATE TABLESPACE "regress_ tblsp" LOCATION ''; +(1 row) + +DROP TABLESPACE "regress_ 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=3.0); +(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=3.0); +(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 = 1.1234567890, 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 (seq_page_cost=1.5, random_page_cost=1.1234567890, 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..6a49100ca14 100644 --- a/src/test/regress/sql/tablespace.sql +++ b/src/test/regress/sql/tablespace.sql @@ -437,3 +437,50 @@ 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 with a space in the name +CREATE TABLESPACE "regress_ tblsp" LOCATION ''; -- ok +-- see that the tablespace ddl is correctly returned +SELECT pg_get_tablespace_ddl('regress_ tblsp'); +DROP TABLESPACE "regress_ 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 = 1.1234567890, 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); -- 2.51.2