From d5dbad978a5f3d4d31cab1e256c2108ed1714740 Mon Sep 17 00:00:00 2001 From: Manni Wood Date: Wed, 19 Nov 2025 16:01:36 -0600 Subject: [PATCH v14] 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/catalog/pg_tablespace.c | 100 +++++++++++++++++++++++ src/backend/utils/adt/ruleutils.c | 40 ++++++++- src/include/catalog/pg_proc.dat | 6 ++ src/include/catalog/pg_tablespace.h | 1 + src/include/utils/ruleutils.h | 2 + src/test/regress/expected/tablespace.out | 69 ++++++++++++++++ src/test/regress/sql/tablespace.sql | 47 +++++++++++ 8 files changed, 308 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/func/func-info.sgml b/doc/src/sgml/func/func-info.sgml index d4508114a48..64c56e0a469 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 or oid ) + text + + + Reconstructs the creating command for a tablespace. + The result is a complete CREATE TABLESPACE statement. + + + + +
+ + + diff --git a/src/backend/catalog/pg_tablespace.c b/src/backend/catalog/pg_tablespace.c index 6aca24c231e..efe6dbe51ca 100644 --- a/src/backend/catalog/pg_tablespace.c +++ b/src/backend/catalog/pg_tablespace.c @@ -17,9 +17,14 @@ #include #include +#include "access/htup_details.h" #include "catalog/pg_tablespace.h" #include "commands/tablespace.h" #include "miscadmin.h" +#include "utils/array.h" +#include "utils/builtins.h" +#include "utils/ruleutils.h" +#include "utils/syscache.h" /* @@ -88,3 +93,98 @@ get_tablespace_location(Oid tablespaceOid) return pstrdup(targetpath); } + +/* + * build_tablespace_ddl_string - Build CREATE TABLESPACE statement as a + * C-string for a tablespace from its 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 %u 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_location(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", quote_literal_cstr(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) + { + /* Start WITH clause */ + appendStringInfoString(&buf, " WITH ("); + + /* Append reloptions to buf */ + get_reloptions(&buf, datum); + + /* Close WITH clause */ + appendStringInfoChar(&buf, ')'); + } + + ReleaseSysCache(tuple); + + /* Finally add semicolon to the statement */ + appendStringInfoChar(&buf, ';'); + + return buf.data; +} diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 556ab057e5a..1c9ef0a597e 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -35,6 +35,7 @@ #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" @@ -536,7 +537,6 @@ static void add_cast_to(StringInfo buf, Oid typid); static char *generate_qualified_type_name(Oid typid); static text *string_to_text(char *str); static char *flatten_reloptions(Oid relid); -static void get_reloptions(StringInfo buf, Datum reloptions); static void get_json_path_spec(Node *path_spec, deparse_context *context, bool showimplicit); static void get_json_table_columns(TableFunc *tf, JsonTablePathScan *scan, @@ -13619,7 +13619,7 @@ string_to_text(char *str) /* * Generate a C string representing a relation options from text[] datum. */ -static void +void get_reloptions(StringInfo buf, Datum reloptions) { Datum *options; @@ -13743,3 +13743,39 @@ get_range_partbound_string(List *bound_datums) 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 aaadfd8c748..77968d1b13f 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/include/catalog/pg_tablespace.h b/src/include/catalog/pg_tablespace.h index 7816d779d8c..b70035832df 100644 --- a/src/include/catalog/pg_tablespace.h +++ b/src/include/catalog/pg_tablespace.h @@ -55,5 +55,6 @@ DECLARE_UNIQUE_INDEX(pg_tablespace_spcname_index, 2698, TablespaceNameIndexId, p MAKE_SYSCACHE(TABLESPACEOID, pg_tablespace_oid_index, 4); extern char *get_tablespace_location(Oid tablespaceOid); +extern char *build_tablespace_ddl_string(const Oid tspaceoid); #endif /* PG_TABLESPACE_H */ diff --git a/src/include/utils/ruleutils.h b/src/include/utils/ruleutils.h index 7ba7d887914..0a7d30de85a 100644 --- a/src/include/utils/ruleutils.h +++ b/src/include/utils/ruleutils.h @@ -54,4 +54,6 @@ extern char *get_range_partbound_string(List *bound_datums); extern char *pg_get_statisticsobjdef_string(Oid statextid); +extern void get_reloptions(StringInfo buf, Datum reloptions); + #endif /* RULEUTILS_H */ diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out index a90e39e5738..aa8ec8da506 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..6298ef1f37b 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); -- 2.52.0