On Thu, Mar 07, 2024 at 08:02:00PM -0600, Justin Pryzby wrote: > As you wrote it, you pass the "defaultAccessMethod" bool to > ATExecSetAccessMethodNoStorage(), which seems odd. Why not just pass > the target amoid as newAccessMethod ?
+ /* + * Check that the table access method exists. + * Use the access method, if specified, otherwise (when not specified) 0 + * for partitioned tables or the configured default AM. + */ + if (amname != NULL) + amoid = get_table_am_oid(amname, false); + else if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) + amoid = 0; + else + amoid = get_table_am_oid(default_table_access_method, false); .. While using this flow to choose the AM oid, that's neater than the versions I could come up with, pretty cool. > When I fooled with this on my side, I called it "chgAccessMethod" to > follow "chgPersistence". I think "is default" isn't the right data > structure. > > Attached a relative patch with my version. Thanks. I've applied the patch to add the DEFAULT clause for now, to ease the work on this patch. > Also: I just realized that instead of adding a bool, we could test > (tab->rewrite & AT_REWRITE_ACCESS_METHOD) != 0 Hmm. I've considered that, but the boolean style is able to do the work, while being more consistent, so I'm OK with what you are doing in your 0002. > +-- Default and AM set in in clause are the same, relam should be set. > > in in? Oops, fixed. I have spent more time reviewing the whole and the tests (I didn't see much value in testing the DEFAULT clause twice for the partitioned table case and there is a test in d61a6cad6418), tweaked a few comments and the documentation, did an indentation and a commit message draft. How does that look to you? The test coverage and the semantics do what we want them to do, so that looks rather reasonable here. A second or even third pair of eyes would not hurt. -- Michael
From 4114c7944c78dbb6eb85320434d942daa77fa4d8 Mon Sep 17 00:00:00 2001 From: Michael Paquier <mich...@paquier.xyz> Date: Fri, 8 Mar 2024 13:24:14 +0900 Subject: [PATCH v4] Allow specifying access method for partitioned tables Partitioned tables gain support for CREATE TABLE .. USING, where specifying an access method can serve as a hint when creating partitions on it. This includes support for ALTER TABLE .. SET ACCESS METHOD, where specifying DEFAULT is equivalent to resetting the partitioned table's relam to 0. Specifying a non-DEFAULT access method will set its relam to not be 0. The historical default of using pg_class.relam as InvalidOid is preserved, corresponding to the case where USING clause is not used. In this case, like previous releases, a partition is created with the access method set by default_table_access_method if its CREATE TABLE query does not specify an access method with a USING clause. The relcache of partitioned tables is not changed: rd_tableam is not set, even if a partitioned table has a relam set. Authors: Justin Pryzby, Soumyadeep Chakraborty Reviewed-by: Michael Paquier, and a few others.. Discussion: https://postgr.es/m/ --- src/include/catalog/pg_class.h | 4 +- src/include/utils/lsyscache.h | 1 + src/backend/commands/tablecmds.c | 172 ++++++++++++++++++++---- 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 | 158 +++++++++++++++++++++- src/test/regress/sql/create_am.sql | 91 ++++++++++++- 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, 471 insertions(+), 39 deletions(-) diff --git a/src/include/catalog/pg_class.h b/src/include/catalog/pg_class.h index 3b7533e7bb..0fc2c093b0 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 that their partitions can inherit it, but they do not set + * rd_tableam; hence, 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 7014be8039..4dd96b93cb 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -183,7 +183,9 @@ typedef struct AlteredTableInfo List *afterStmts; /* List of utility command parsetrees */ bool verify_new_notnull; /* T if we should recheck NOT NULL */ int rewrite; /* Reason for forced rewrite, if any */ - Oid newAccessMethod; /* new access method; 0 means no change */ + bool chgAccessMethod; /* T if SET ACCESS METHOD is used */ + Oid newAccessMethod; /* new access method; 0 means no change, + * if above is true */ Oid newTableSpace; /* new tablespace; 0 means no change */ bool chgPersistence; /* T if SET LOGGED/UNLOGGED is used */ char newrelpersistence; /* if above is true */ @@ -589,6 +591,7 @@ 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); @@ -703,7 +706,6 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId, Oid ofTypeId; ObjectAddress address; LOCKMODE parentLockmode; - const char *accessMethod = NULL; Oid accessMethodId = InvalidOid; /* @@ -956,20 +958,25 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId, * a type of relation that needs one, use the default. */ if (stmt->accessMethod != NULL) + accessMethodId = get_table_am_oid(stmt->accessMethod, false); + else if (stmt->partbound) { - accessMethod = stmt->accessMethod; - - if (partitioned) - ereport(ERROR, - (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), - errmsg("specifying a table access method is not supported on a partitioned table"))); + /* + * 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 if (RELKIND_HAS_TABLE_AM(relkind)) - accessMethod = default_table_access_method; + 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. Partitioned tables default to + * InvalidOid without an access method specified. + */ + 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 @@ -5045,14 +5052,8 @@ 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)) + if (tab->chgAccessMethod) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot have multiple SET ACCESS METHOD subcommands"))); @@ -5407,6 +5408,14 @@ 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 && + tab->chgAccessMethod) + ATExecSetAccessMethodNoStorage(rel, tab->newAccessMethod); break; case AT_SetTableSpace: /* SET TABLESPACE */ @@ -5812,7 +5821,7 @@ ATRewriteTables(AlterTableStmt *parsetree, List **wqueue, LOCKMODE lockmode, * Select destination access method (same as original unless user * requested a change) */ - if (OidIsValid(tab->newAccessMethod)) + if (tab->chgAccessMethod) NewAccessMethod = tab->newAccessMethod; else NewAccessMethod = OldHeap->rd_rel->relam; @@ -6399,6 +6408,7 @@ ATGetQueueEntry(List **wqueue, Relation rel) tab->relkind = rel->rd_rel->relkind; tab->oldDesc = CreateTupleDescCopyConstr(RelationGetDescr(rel)); tab->newAccessMethod = InvalidOid; + tab->chgAccessMethod = false; tab->newTableSpace = InvalidOid; tab->newrelpersistence = RELPERSISTENCE_PERMANENT; tab->chgPersistence = false; @@ -15201,17 +15211,32 @@ ATExecDropCluster(Relation rel, LOCKMODE lockmode) * Preparation phase for SET ACCESS METHOD * * Check that access method exists. If it is the same as the table's current - * access method, it is a no-op. Otherwise, a table rewrite is necessary. + * access method, it is a no-op. Otherwise, a table rewrite is necessary for + * relations with storage. * If amname is NULL, select default_table_access_method as access method. + * + * Partitioned tables may use InvalidOid to assign the default AM to partitions + * when created. This operation is a no-op if a DEFAULT was given and the + * partitioned table uses InvalidOid as relam, or if the relam and the access + * method specified match. */ static void ATPrepSetAccessMethod(AlteredTableInfo *tab, Relation rel, const char *amname) { Oid amoid; - /* Check that the table access method exists */ - amoid = get_table_am_oid(amname ? amname : default_table_access_method, - false); + /* + * Check that the table access method exists. + * + * Use the access method specified, otherwise, when not specified, use + * InvalidOid for partitioned tables or the configured default AM. + */ + if (amname != NULL) + amoid = get_table_am_oid(amname, false); + else if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) + amoid = InvalidOid; + else + amoid = get_table_am_oid(default_table_access_method, false); if (rel->rd_rel->relam == amoid) return; @@ -15219,6 +15244,7 @@ ATPrepSetAccessMethod(AlteredTableInfo *tab, Relation rel, const char *amname) /* Save info for Phase 3 to do the real work */ tab->rewrite |= AT_REWRITE_ACCESS_METHOD; tab->newAccessMethod = amoid; + tab->chgAccessMethod = true; } /* @@ -15543,6 +15569,102 @@ 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); + + /* + * Shouldn't be called on relations having storage; these are processed in + * phase 3. + */ + Assert(!RELKIND_HAS_STORAGE(rel->rd_rel->relkind)); + + /* 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; + + /* 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 new access method is InvalidOid (default case). Be very careful + * that this has to compare the previous value stored in pg_class with the + * new one. + */ + if (!OidIsValid(oldAccessMethodId) && OidIsValid(rd_rel->relam)) + { + 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, rd_rel->relam); + recordDependencyOn(&relobj, &referenced, DEPENDENCY_NORMAL); + } + else if (OidIsValid(oldAccessMethodId) && + !OidIsValid(rd_rel->relam)) + { + /* + * 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) && + OidIsValid(rd_rel->relam)); + + /* Both are valid, so update the dependency */ + changeDependencyFor(RelationRelationId, reloid, + AccessMethodRelationId, + oldAccessMethodId, rd_rel->relam); + } + + 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 6418d1c6eb..26368ffcc9 100644 --- a/src/backend/utils/cache/lsyscache.c +++ b/src/backend/utils/cache/lsyscache.c @@ -2069,6 +2069,28 @@ 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 4d339ee795..18c6044238 100644 --- a/src/backend/utils/cache/relcache.c +++ b/src/backend/utils/cache/relcache.c @@ -1208,6 +1208,13 @@ 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 are 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 10cbf02beb..ec406bff29 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 8d73e21356..a27805a8f5 100644 --- a/src/test/regress/expected/create_am.out +++ b/src/test/regress/expected/create_am.out @@ -176,9 +176,16 @@ SELECT f1 FROM tableam_tblmv_heap2 ORDER BY f1; 1 (1 row) --- CREATE TABLE .. PARTITION BY doesn't not support USING +-- CREATE TABLE .. PARTITION BY supports USING. CREATE TABLE tableam_parted_heap2 (a text, b int) PARTITION BY list (a) USING heap2; -ERROR: specifying a table access method is not supported on a partitioned table +SELECT a.amname FROM pg_class c, pg_am a + WHERE c.relname = 'tableam_parted_heap2' AND a.oid = c.relam; + amname +-------- + heap2 +(1 row) + +DROP TABLE tableam_parted_heap2; CREATE TABLE tableam_parted_heap2 (a text, b int) PARTITION BY list (a); -- new partitions will inherit from the current default, rather the partition root SET default_table_access_method = 'heap'; @@ -336,12 +343,151 @@ 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) + +-- Default and AM set in the clause are the same, relam should be set. +SET LOCAL default_table_access_method = 'heap2'; +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; + amname +-------- + heap2 +(1 row) + +-- Reset to default +ALTER TABLE am_partitioned SET ACCESS METHOD DEFAULT; +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_0 PARTITION OF am_partitioned + FOR VALUES WITH (MODULUS 10, REMAINDER 0); +SET LOCAL default_table_access_method = 'heap2'; +CREATE TABLE am_partitioned_1 PARTITION OF am_partitioned + FOR VALUES WITH (MODULUS 10, REMAINDER 1); +SET LOCAL default_table_access_method = 'heap'; +ALTER TABLE am_partitioned SET ACCESS METHOD heap2; +CREATE TABLE am_partitioned_2 PARTITION OF am_partitioned + FOR VALUES WITH (MODULUS 10, 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_3 PARTITION OF am_partitioned + FOR VALUES WITH (MODULUS 10, REMAINDER 3); +-- Partitioned table with relam at 0 +ALTER TABLE am_partitioned SET ACCESS METHOD DEFAULT; +CREATE TABLE am_partitioned_5p PARTITION OF am_partitioned + FOR VALUES WITH (MODULUS 10, REMAINDER 5) PARTITION BY hash(y); +-- Partitions of this partitioned table inherit default AM at creation +-- time. +CREATE TABLE am_partitioned_5p1 PARTITION OF am_partitioned_5p + FOR VALUES WITH (MODULUS 10, REMAINDER 1); +-- Partitioned table with relam set. +ALTER TABLE am_partitioned SET ACCESS METHOD heap2; +CREATE TABLE am_partitioned_6p PARTITION OF am_partitioned + FOR VALUES WITH (MODULUS 10, REMAINDER 6) PARTITION BY hash(y); +-- Partitions of this partitioned table inherit its AM. +CREATE TABLE am_partitioned_6p1 PARTITION OF am_partitioned_6p + FOR VALUES WITH (MODULUS 10, REMAINDER 1); +SELECT c.relname, a.amname FROM pg_class c, pg_am a + WHERE c.relam = a.oid AND + c.relname LIKE 'am_partitioned%' +UNION ALL +SELECT c.relname, 'default' FROM pg_class c + WHERE c.relam = 0 + AND c.relname LIKE 'am_partitioned%' ORDER BY 1; + relname | amname +--------------------+--------- + am_partitioned | heap2 + am_partitioned_0 | heap + am_partitioned_1 | heap2 + am_partitioned_2 | heap2 + am_partitioned_3 | heap + am_partitioned_5p | default + am_partitioned_5p1 | heap + am_partitioned_6p | heap2 + am_partitioned_6p1 | heap2 +(9 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 606ee4cb24..adff0079f9 100644 --- a/src/test/regress/sql/create_am.sql +++ b/src/test/regress/sql/create_am.sql @@ -124,8 +124,11 @@ CREATE SEQUENCE tableam_seq_heap2 USING heap2; CREATE MATERIALIZED VIEW tableam_tblmv_heap2 USING heap2 AS SELECT * FROM tableam_tbl_heap2; SELECT f1 FROM tableam_tblmv_heap2 ORDER BY f1; --- CREATE TABLE .. PARTITION BY doesn't not support USING +-- CREATE TABLE .. PARTITION BY supports USING. CREATE TABLE tableam_parted_heap2 (a text, b int) PARTITION BY list (a) USING heap2; +SELECT a.amname FROM pg_class c, pg_am a + WHERE c.relname = 'tableam_parted_heap2' AND a.oid = c.relam; +DROP TABLE tableam_parted_heap2; CREATE TABLE tableam_parted_heap2 (a text, b int) PARTITION BY list (a); -- new partitions will inherit from the current default, rather the partition root @@ -213,11 +216,91 @@ ALTER TABLE heaptable SET ACCESS METHOD DEFAULT, 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; +-- Default and AM set in the clause are the same, relam should be set. +SET LOCAL default_table_access_method = 'heap2'; +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; +-- Reset to default +ALTER TABLE am_partitioned SET ACCESS METHOD DEFAULT; +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_0 PARTITION OF am_partitioned + FOR VALUES WITH (MODULUS 10, REMAINDER 0); +SET LOCAL default_table_access_method = 'heap2'; +CREATE TABLE am_partitioned_1 PARTITION OF am_partitioned + FOR VALUES WITH (MODULUS 10, REMAINDER 1); +SET LOCAL default_table_access_method = 'heap'; +ALTER TABLE am_partitioned SET ACCESS METHOD heap2; +CREATE TABLE am_partitioned_2 PARTITION OF am_partitioned + FOR VALUES WITH (MODULUS 10, REMAINDER 2); +ALTER TABLE am_partitioned SET ACCESS METHOD DEFAULT; +SELECT relam FROM pg_class WHERE relname = 'am_partitioned'; +CREATE TABLE am_partitioned_3 PARTITION OF am_partitioned + FOR VALUES WITH (MODULUS 10, REMAINDER 3); +-- Partitioned table with relam at 0 +ALTER TABLE am_partitioned SET ACCESS METHOD DEFAULT; +CREATE TABLE am_partitioned_5p PARTITION OF am_partitioned + FOR VALUES WITH (MODULUS 10, REMAINDER 5) PARTITION BY hash(y); +-- Partitions of this partitioned table inherit default AM at creation +-- time. +CREATE TABLE am_partitioned_5p1 PARTITION OF am_partitioned_5p + FOR VALUES WITH (MODULUS 10, REMAINDER 1); +-- Partitioned table with relam set. +ALTER TABLE am_partitioned SET ACCESS METHOD heap2; +CREATE TABLE am_partitioned_6p PARTITION OF am_partitioned + FOR VALUES WITH (MODULUS 10, REMAINDER 6) PARTITION BY hash(y); +-- Partitions of this partitioned table inherit its AM. +CREATE TABLE am_partitioned_6p1 PARTITION OF am_partitioned_6p + FOR VALUES WITH (MODULUS 10, REMAINDER 1); +SELECT c.relname, a.amname FROM pg_class c, pg_am a + WHERE c.relam = a.oid AND + c.relname LIKE 'am_partitioned%' +UNION ALL +SELECT c.relname, 'default' FROM pg_class c + WHERE c.relam = 0 + 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 0ae97d1ada..e4fcacb610 100644 --- a/doc/src/sgml/catalogs.sgml +++ b/doc/src/sgml/catalogs.sgml @@ -1989,8 +1989,9 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l </para> <para> 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. </para></entry> </row> diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml index 96e3d77605..b6e794e6ce 100644 --- a/doc/src/sgml/ref/alter_table.sgml +++ b/doc/src/sgml/ref/alter_table.sgml @@ -737,6 +737,14 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM <literal>DEFAULT</literal> changes the access method of the table to <xref linkend="guc-default-table-access-method"/>. </para> + <para> + 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 <literal>USING</literal> clause. Using + <varname>DEFAULT</varname> switches the partitioned table to use + <varname>default_table_access_method</varname> when new partitions are + created. + </para> </listitem> </varlistentry> 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 <replaceable class="parameter">numeric_literal</replaceable>, REM method is chosen for the new table. See <xref linkend="guc-default-table-access-method"/> for more information. </para> + <para> + When creating a partition, the table access method is the access method + of its partitioned table, if set. + </para> </listitem> </varlistentry> -- 2.43.0
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