From 39ddc35db15222a7b5d6ee94fa27023e12112ae9 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Thu, 29 Jun 2023 07:53:16 +0900 Subject: [PATCH v3] Fix pg_depend entry to AMs after ALTER TABLE .. SET ACCESS METHOD ALTER TABLE .. SET ACCESS METHOD was not registering a dependency to the new access method with the relation altered in its rewrite phase, making possible the drop of an access method even if there are relations that depend on it. During the rewrite, a temporary relation is created to build the new relation files before swapping the new and old files, and, while the temporary relation was registering a correct dependency to the new AM, the old relation did not do that. A dependency on the access method is added when the relation files are swapped, which is the point where pg_class is updated with the new access method. Materialized views and tables use the same code path, hence both were impacted. Backpatch down to 15, where this command has been introduced. Reported-by: Alexander Lakhin Reviewed-by: Nathan Bossart, Andres Freund Discussion: https://postgr.es/m/18000-9145c25b1af475ca@postgresql.org Backpatch-through: 15 --- src/backend/commands/cluster.c | 29 +++++++++++++++++++++++ src/bin/pg_waldump/pg_waldump.c | 3 ++- src/bin/pg_waldump/t/002_save_fullpage.pl | 9 +++---- src/test/regress/expected/create_am.out | 29 +++++++++++++++++++++++ src/test/regress/sql/create_am.sql | 18 ++++++++++++++ doc/src/sgml/ref/pg_waldump.sgml | 9 ++++++- 6 files changed, 91 insertions(+), 6 deletions(-) diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c index 3bfabb6d10..03b24ab90f 100644 --- a/src/backend/commands/cluster.c +++ b/src/backend/commands/cluster.c @@ -1070,6 +1070,8 @@ swap_relation_files(Oid r1, Oid r2, bool target_is_pg_class, relfilenumber2; RelFileNumber swaptemp; char swptmpchr; + Oid relam1, + relam2; /* We need writable copies of both pg_class tuples. */ relRelation = table_open(RelationRelationId, RowExclusiveLock); @@ -1086,6 +1088,8 @@ swap_relation_files(Oid r1, Oid r2, bool target_is_pg_class, relfilenumber1 = relform1->relfilenode; relfilenumber2 = relform2->relfilenode; + relam1 = relform1->relam; + relam2 = relform2->relam; if (RelFileNumberIsValid(relfilenumber1) && RelFileNumberIsValid(relfilenumber2)) @@ -1257,6 +1261,31 @@ swap_relation_files(Oid r1, Oid r2, bool target_is_pg_class, CacheInvalidateRelcacheByTuple(reltup2); } + /* + * Now that pg_class has been updated with its relevant information for + * the swap, update the dependency of the relations to point to their new + * table AM, if it has changed. + */ + if (relam1 != relam2) + { + if (changeDependencyFor(RelationRelationId, + r1, + AccessMethodRelationId, + relam1, + relam2) != 1) + elog(ERROR, "failed to change access method dependency for relation \"%s.%s\"", + get_namespace_name(get_rel_namespace(r1)), + get_rel_name(r1)); + if (changeDependencyFor(RelationRelationId, + r2, + AccessMethodRelationId, + relam2, + relam1) != 1) + elog(ERROR, "failed to change access method dependency for relation \"%s.%s\"", + get_namespace_name(get_rel_namespace(r2)), + get_rel_name(r2)); + } + /* * Post alter hook for modified relations. The change to r2 is always * internal, but r1 depends on the invocation context. diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c index c6d3ae6344..96845e1a1a 100644 --- a/src/bin/pg_waldump/pg_waldump.c +++ b/src/bin/pg_waldump/pg_waldump.c @@ -518,7 +518,8 @@ XLogRecordSaveFPWs(XLogReaderState *record, const char *savepath) else pg_fatal("invalid fork number: %u", fork); - snprintf(filename, MAXPGPATH, "%s/%08X-%08X.%u.%u.%u.%u%s", savepath, + snprintf(filename, MAXPGPATH, "%s/%08X-%08X-%08X.%u.%u.%u.%u%s", savepath, + record->seg.ws_tli, LSN_FORMAT_ARGS(record->ReadRecPtr), rnode.spcOid, rnode.dbOid, rnode.relNumber, blk, forkname); diff --git a/src/bin/pg_waldump/t/002_save_fullpage.pl b/src/bin/pg_waldump/t/002_save_fullpage.pl index 831ffdefef..f0725805f2 100644 --- a/src/bin/pg_waldump/t/002_save_fullpage.pl +++ b/src/bin/pg_waldump/t/002_save_fullpage.pl @@ -79,15 +79,16 @@ $node->command_ok( 'pg_waldump with --save-fullpage runs'); # This regexp will match filenames formatted as: -# XXXXXXXX-XXXXXXXX.DBOID.TLOID.NODEOID.dd_fork with the components being: -# - WAL LSN in hex format, -# - Tablespace OID (0 for global) +# TLI-LSNh-LSNl.TBLSPCOID.DBOID.NODEOID.dd_fork with the components being: +# - Timeline ID in hex format. +# - WAL LSN in hex format, as two 8-character numbers. +# - Tablespace OID (0 for global). # - Database OID. # - Relfilenode. # - Block number. # - Fork this block came from (vm, init, fsm, or main). my $file_re = - qr/^([0-9A-F]{8})-([0-9A-F]{8})[.][0-9]+[.][0-9]+[.][0-9]+[.][0-9]+(?:_vm|_init|_fsm|_main)?$/; + qr/^[0-9A-F]{8}-([0-9A-F]{8})-([0-9A-F]{8})[.][0-9]+[.][0-9]+[.][0-9]+[.][0-9]+(?:_vm|_init|_fsm|_main)?$/; my $file_count = 0; diff --git a/src/test/regress/expected/create_am.out b/src/test/regress/expected/create_am.out index e9a9283d7a..b50293d514 100644 --- a/src/test/regress/expected/create_am.out +++ b/src/test/regress/expected/create_am.out @@ -240,6 +240,35 @@ SELECT amname FROM pg_class c, pg_am am heap (1 row) +-- Switching to heap2 adds new dependency entry to the AM. +ALTER TABLE heaptable SET ACCESS METHOD heap2; +SELECT pg_describe_object(classid, objid, objsubid) as obj, + pg_describe_object(refclassid, refobjid, refobjsubid) as objref, + deptype + FROM pg_depend + WHERE classid = 'pg_class'::regclass AND + objid = 'heaptable'::regclass + ORDER BY 1, 2; + obj | objref | deptype +-----------------+---------------------+--------- + table heaptable | access method heap2 | n + table heaptable | schema public | n +(2 rows) + +-- Switching to heap should not have a dependency entry to the AM. +ALTER TABLE heaptable SET ACCESS METHOD heap; +SELECT pg_describe_object(classid, objid, objsubid) as obj, + pg_describe_object(refclassid, refobjid, refobjsubid) as objref, + deptype + FROM pg_depend + WHERE classid = 'pg_class'::regclass AND + objid = 'heaptable'::regclass + ORDER BY 1, 2; + obj | objref | deptype +-----------------+---------------+--------- + table heaptable | schema public | n +(1 row) + ALTER TABLE heaptable SET ACCESS METHOD heap2; SELECT amname FROM pg_class c, pg_am am WHERE c.relam = am.oid AND c.oid = 'heaptable'::regclass; diff --git a/src/test/regress/sql/create_am.sql b/src/test/regress/sql/create_am.sql index 256884c959..2785ffd8bb 100644 --- a/src/test/regress/sql/create_am.sql +++ b/src/test/regress/sql/create_am.sql @@ -166,6 +166,24 @@ CREATE TABLE heaptable USING heap AS SELECT a, repeat(a::text, 100) FROM generate_series(1,9) AS a; SELECT amname FROM pg_class c, pg_am am WHERE c.relam = am.oid AND c.oid = 'heaptable'::regclass; +-- Switching to heap2 adds new dependency entry to the AM. +ALTER TABLE heaptable SET ACCESS METHOD heap2; +SELECT pg_describe_object(classid, objid, objsubid) as obj, + pg_describe_object(refclassid, refobjid, refobjsubid) as objref, + deptype + FROM pg_depend + WHERE classid = 'pg_class'::regclass AND + objid = 'heaptable'::regclass + ORDER BY 1, 2; +-- Switching to heap should not have a dependency entry to the AM. +ALTER TABLE heaptable SET ACCESS METHOD heap; +SELECT pg_describe_object(classid, objid, objsubid) as obj, + pg_describe_object(refclassid, refobjid, refobjsubid) as objref, + deptype + FROM pg_depend + WHERE classid = 'pg_class'::regclass AND + objid = 'heaptable'::regclass + ORDER BY 1, 2; ALTER TABLE heaptable SET ACCESS METHOD heap2; SELECT amname FROM pg_class c, pg_am am WHERE c.relam = am.oid AND c.oid = 'heaptable'::regclass; diff --git a/doc/src/sgml/ref/pg_waldump.sgml b/doc/src/sgml/ref/pg_waldump.sgml index e5f9637847..4592d6016a 100644 --- a/doc/src/sgml/ref/pg_waldump.sgml +++ b/doc/src/sgml/ref/pg_waldump.sgml @@ -283,7 +283,7 @@ PostgreSQL documentation The full page images are saved with the following file name format: - LSN.RELTABLESPACE.DATOID.RELNODE.BLKNOFORK + TIMELINE-LSN.RELTABLESPACE.DATOID.RELNODE.BLKNOFORK The file names are composed of the following parts: @@ -296,6 +296,13 @@ PostgreSQL documentation + + TIMELINE + The timeline of the WAL segment file where the record + is located formatted as one 8-character hexadecimal number + %08X + + LSN The LSN of the record with this image, -- 2.40.1