Manni Wood <[email protected]> [image: Attachments]8:09 AM (13 minutes ago) to *Álvaro*, *psql-hackers*, *Chao*, *Nishant*, *Jim* Hello! After waiting all weekend, my Friday e-mail did not get through psql-hackers, so I am sending again, using Álvaro's advice to send to lists.postgresql.org rather than plain postgresql.org.
Here is the original mail: Hello, Chao Li! Thank you for the improvements to my patch, helping it follow more of Postgres's coding conventions. Much appreciated. I have attached v13 of the patch. Now that Álvaro has merged the contents of the 0001 patch, I assume this v13 patch can be 0001 and not 0002. On Thu, Nov 13, 2025 at 1:59 PM Manni Wood <[email protected]> wrote: > > > On Thu, Nov 13, 2025 at 12:20 PM Álvaro Herrera <[email protected]> > wrote: > >> On 2025-Nov-13, Manni Wood wrote: >> >> > Hello, Chao Li! >> > >> > Thank you for the improvements to my patch, helping it follow more of >> > Postgres's coding conventions. Much appreciated. >> > >> > I have tried attaching a v13 patch and [email protected] is >> > saying my message is undeliverable to [email protected], so >> I'm >> > just sending this message without the attachment to see if it gets >> through >> > and to thank you for looking at the patch. >> >> The problem is just that lists under @postgresql.org are temporarily >> broken. They should be fixed later today. I suggest you do nothing for >> now; your message might be delivered later if it's still in the server >> queue (though maybe not -- not sure). >> >> The same addresses but under @lists.postgresql.org would work just fine. >> I suggest you use that in new threads (or even in existing threads, going >> forward, by manually editing the CC line). But as I said, for the >> current thread I suggest not to resend your message to avoid potential >> duplicated messages. >> >> -- >> Álvaro Herrera Breisgau, Deutschland — >> https://www.EnterpriseDB.com/ >> "We're here to devour each other alive" (Hobbes) >> > > OK, thanks, Álvaro; I will hold off with e-mails until later to see if my > already-sent ones eventually get through. > -- > -- Manni Wood EDB: https://www.enterprisedb.com > -- -- Manni Wood EDB: https://www.enterprisedb.com
From 04d4e447cfa2bcd8124f3b44fc4ea2ba6a813455 Mon Sep 17 00:00:00 2001 From: Manni Wood <[email protected]> Date: Thu, 13 Nov 2025 10:10:03 -0600 Subject: [PATCH v13] 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 <[email protected]> and Nishant Sharma <[email protected]> Reviewers: Vaibhav Dalvi, Ian Barwick, Jim Jones, Álvaro Herrera Discussion: https://www.postgresql.org/message-id/flat/CAKWEB6rmnmGKUA87Zmq-s=b3scsnj02c0kobqjnbl2ajfpw...@mail.gmail.com --- doc/src/sgml/func/func-info.sgml | 45 +++++++++ src/backend/catalog/pg_tablespace.c | 118 +++++++++++++++++++++++ src/backend/utils/adt/ruleutils.c | 37 +++++++ src/include/catalog/pg_proc.dat | 6 ++ src/include/catalog/pg_tablespace.h | 1 + src/test/regress/expected/tablespace.out | 69 +++++++++++++ src/test/regress/sql/tablespace.sql | 47 +++++++++ 7 files changed, 323 insertions(+) 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} </sect2> + <sect2 id="functions-get-object-ddl"> + <title>Get Object DDL Functions</title> + + <para> + The functions shown in <xref linkend="functions-get-object-ddl-table"/> + print the DDL statements for various database objects. + (This is a decompiled reconstruction, not the original text + of the command.) + </para> + + <table id="functions-get-object-ddl-table"> + <title>Get Object DDL Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>pg_get_tablespace_ddl</primary> + </indexterm> + <function>pg_get_tablespace_ddl</function> + ( <parameter>tablespace</parameter> <type>name</type> or <type>oid</type> ) + <returnvalue>text</returnvalue> + </para> + <para> + Reconstructs the creating command for a tablespace. + The result is a complete <command>CREATE TABLESPACE</command> statement. + </para></entry> + </row> + </tbody> + </tgroup> + </table> + + </sect2> + </sect1> diff --git a/src/backend/catalog/pg_tablespace.c b/src/backend/catalog/pg_tablespace.c index 6aca24c231e..8f04ef7a6b2 100644 --- a/src/backend/catalog/pg_tablespace.c +++ b/src/backend/catalog/pg_tablespace.c @@ -17,9 +17,13 @@ #include <unistd.h> #include <sys/stat.h> +#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/syscache.h" /* @@ -88,3 +92,117 @@ 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) + { + 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 */ + appendStringInfo(&buf, "%s, ", TextDatumGetCString(optdatums[i])); + } + + /* 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; +} diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 556ab057e5a..dc5365fbeae 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" @@ -13743,3 +13744,39 @@ 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 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/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/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
