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[PATCH v2 4/4] Extra tests 194+ messages / 5 participants [nested] [flat]
* [PATCH v2 4/4] Extra tests @ 2025-09-04 16:28 Nikolay Shaplov <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: Nikolay Shaplov @ 2025-09-04 16:28 UTC (permalink / raw) Add more tests for ternary reloptions in dummy_index_am module --- src/test/modules/dummy_index_am/README | 1 + .../modules/dummy_index_am/dummy_index_am.c | 36 +++++++++++++----- .../dummy_index_am/expected/reloptions.out | 38 +++++++++++++++++-- .../modules/dummy_index_am/sql/reloptions.sql | 16 ++++++++ src/test/regress/expected/reloptions.out | 4 +- src/test/regress/sql/reloptions.sql | 4 +- 6 files changed, 81 insertions(+), 18 deletions(-) diff --git a/src/test/modules/dummy_index_am/README b/src/test/modules/dummy_index_am/README index 61510f02fa..d80aff0db1 100644 --- a/src/test/modules/dummy_index_am/README +++ b/src/test/modules/dummy_index_am/README @@ -6,6 +6,7 @@ access method, whose code is kept a maximum simple. This includes tests for all relation option types: - boolean +- ternary - enum - integer - real diff --git a/src/test/modules/dummy_index_am/dummy_index_am.c b/src/test/modules/dummy_index_am/dummy_index_am.c index 94ef639b6f..bf8446ddc6 100644 --- a/src/test/modules/dummy_index_am/dummy_index_am.c +++ b/src/test/modules/dummy_index_am/dummy_index_am.c @@ -22,7 +22,7 @@ PG_MODULE_MAGIC; /* parse table for fillRelOptions */ -static relopt_parse_elt di_relopt_tab[6]; +static relopt_parse_elt di_relopt_tab[8]; /* Kind of relation options for dummy index */ static relopt_kind di_relopt_kind; @@ -40,6 +40,8 @@ typedef struct DummyIndexOptions int option_int; double option_real; bool option_bool; + ternary option_ternary1; + ternary option_ternary2; DummyAmEnum option_enum; int option_string_val_offset; int option_string_null_offset; @@ -96,23 +98,37 @@ create_reloptions_table(void) di_relopt_tab[2].opttype = RELOPT_TYPE_BOOL; di_relopt_tab[2].offset = offsetof(DummyIndexOptions, option_bool); + add_ternary_reloption(di_relopt_kind, "option_ternary1", + "First ternary option for dummy_index_am", + TERNARY_UNSET, NULL, AccessExclusiveLock); + di_relopt_tab[3].optname = "option_ternary1"; + di_relopt_tab[3].opttype = RELOPT_TYPE_TERNARY; + di_relopt_tab[3].offset = offsetof(DummyIndexOptions, option_ternary1); + + add_ternary_reloption(di_relopt_kind, "option_ternary2", + "Second ternary option for dummy_index_am", + TERNARY_TRUE, "do_not_know_yet", AccessExclusiveLock); + di_relopt_tab[4].optname = "option_ternary2"; + di_relopt_tab[4].opttype = RELOPT_TYPE_TERNARY; + di_relopt_tab[4].offset = offsetof(DummyIndexOptions, option_ternary2); + add_enum_reloption(di_relopt_kind, "option_enum", "Enum option for dummy_index_am", dummyAmEnumValues, DUMMY_AM_ENUM_ONE, "Valid values are \"one\" and \"two\".", AccessExclusiveLock); - di_relopt_tab[3].optname = "option_enum"; - di_relopt_tab[3].opttype = RELOPT_TYPE_ENUM; - di_relopt_tab[3].offset = offsetof(DummyIndexOptions, option_enum); + di_relopt_tab[5].optname = "option_enum"; + di_relopt_tab[5].opttype = RELOPT_TYPE_ENUM; + di_relopt_tab[5].offset = offsetof(DummyIndexOptions, option_enum); add_string_reloption(di_relopt_kind, "option_string_val", "String option for dummy_index_am with non-NULL default", "DefaultValue", &validate_string_option, AccessExclusiveLock); - di_relopt_tab[4].optname = "option_string_val"; - di_relopt_tab[4].opttype = RELOPT_TYPE_STRING; - di_relopt_tab[4].offset = offsetof(DummyIndexOptions, + di_relopt_tab[6].optname = "option_string_val"; + di_relopt_tab[6].opttype = RELOPT_TYPE_STRING; + di_relopt_tab[6].offset = offsetof(DummyIndexOptions, option_string_val_offset); /* @@ -123,9 +139,9 @@ create_reloptions_table(void) NULL, /* description */ NULL, &validate_string_option, AccessExclusiveLock); - di_relopt_tab[5].optname = "option_string_null"; - di_relopt_tab[5].opttype = RELOPT_TYPE_STRING; - di_relopt_tab[5].offset = offsetof(DummyIndexOptions, + di_relopt_tab[7].optname = "option_string_null"; + di_relopt_tab[7].opttype = RELOPT_TYPE_STRING; + di_relopt_tab[7].offset = offsetof(DummyIndexOptions, option_string_null_offset); } diff --git a/src/test/modules/dummy_index_am/expected/reloptions.out b/src/test/modules/dummy_index_am/expected/reloptions.out index c873a80bb7..ad1b2ea639 100644 --- a/src/test/modules/dummy_index_am/expected/reloptions.out +++ b/src/test/modules/dummy_index_am/expected/reloptions.out @@ -18,6 +18,8 @@ SET client_min_messages TO 'notice'; CREATE INDEX dummy_test_idx ON dummy_test_tab USING dummy_index_am (i) WITH ( option_bool = false, + option_ternary1, + option_ternary2 = off, option_int = 5, option_real = 3.1, option_enum = 'two', @@ -31,16 +33,20 @@ SELECT unnest(reloptions) FROM pg_class WHERE relname = 'dummy_test_idx'; unnest ------------------------ option_bool=false + option_ternary1=true + option_ternary2=off option_int=5 option_real=3.1 option_enum=two option_string_val=null option_string_null=val -(6 rows) +(8 rows) -- ALTER INDEX .. SET ALTER INDEX dummy_test_idx SET (option_int = 10); ALTER INDEX dummy_test_idx SET (option_bool = true); +ALTER INDEX dummy_test_idx SET (option_ternary1 = false); +ALTER INDEX dummy_test_idx SET (option_ternary2 = Do_Not_Know_YET); ALTER INDEX dummy_test_idx SET (option_real = 3.2); ALTER INDEX dummy_test_idx SET (option_string_val = 'val2'); ALTER INDEX dummy_test_idx SET (option_string_null = NULL); @@ -49,19 +55,23 @@ ALTER INDEX dummy_test_idx SET (option_enum = 'three'); ERROR: invalid value for enum option "option_enum": three DETAIL: Valid values are "one" and "two". SELECT unnest(reloptions) FROM pg_class WHERE relname = 'dummy_test_idx'; - unnest -------------------------- + unnest +--------------------------------- option_int=10 option_bool=true + option_ternary1=false + option_ternary2=do_not_know_yet option_real=3.2 option_string_val=val2 option_string_null=null option_enum=one -(6 rows) +(8 rows) -- ALTER INDEX .. RESET ALTER INDEX dummy_test_idx RESET (option_int); ALTER INDEX dummy_test_idx RESET (option_bool); +ALTER INDEX dummy_test_idx RESET (option_ternary1); +ALTER INDEX dummy_test_idx RESET (option_ternary2); ALTER INDEX dummy_test_idx RESET (option_real); ALTER INDEX dummy_test_idx RESET (option_enum); ALTER INDEX dummy_test_idx RESET (option_string_val); @@ -100,6 +110,26 @@ SELECT unnest(reloptions) FROM pg_class WHERE relname = 'dummy_test_idx'; (1 row) ALTER INDEX dummy_test_idx RESET (option_bool); +-- Ternary +ALTER INDEX dummy_test_idx SET (option_ternary1 = 4); -- error +ERROR: invalid value for ternary option "option_ternary1": 4 +ALTER INDEX dummy_test_idx SET (option_ternary1 = 1); -- ok, as true +ALTER INDEX dummy_test_idx SET (option_ternary1 = 3.4); -- error +ERROR: invalid value for ternary option "option_ternary1": 3.4 +ALTER INDEX dummy_test_idx SET (option_ternary1 = 'val4'); -- error +ERROR: invalid value for ternary option "option_ternary1": val4 +ALTER INDEX dummy_test_idx SET (option_ternary1 = 'do_not_know_yet'); -- error. Valid for ternary2 not for ternary1 +ERROR: invalid value for ternary option "option_ternary1": do_not_know_yet +ALTER INDEX dummy_test_idx SET (option_ternary2 = 'do_not_know_yet'); -- ok +SELECT unnest(reloptions) FROM pg_class WHERE relname = 'dummy_test_idx'; + unnest +--------------------------------- + option_ternary1=1 + option_ternary2=do_not_know_yet +(2 rows) + +ALTER INDEX dummy_test_idx RESET (option_ternary1); +ALTER INDEX dummy_test_idx RESET (option_ternary2); -- Float ALTER INDEX dummy_test_idx SET (option_real = 4); -- ok ALTER INDEX dummy_test_idx SET (option_real = true); -- error diff --git a/src/test/modules/dummy_index_am/sql/reloptions.sql b/src/test/modules/dummy_index_am/sql/reloptions.sql index 6749d763e6..123540905a 100644 --- a/src/test/modules/dummy_index_am/sql/reloptions.sql +++ b/src/test/modules/dummy_index_am/sql/reloptions.sql @@ -18,6 +18,8 @@ SET client_min_messages TO 'notice'; CREATE INDEX dummy_test_idx ON dummy_test_tab USING dummy_index_am (i) WITH ( option_bool = false, + option_ternary1, + option_ternary2 = off, option_int = 5, option_real = 3.1, option_enum = 'two', @@ -30,6 +32,8 @@ SELECT unnest(reloptions) FROM pg_class WHERE relname = 'dummy_test_idx'; -- ALTER INDEX .. SET ALTER INDEX dummy_test_idx SET (option_int = 10); ALTER INDEX dummy_test_idx SET (option_bool = true); +ALTER INDEX dummy_test_idx SET (option_ternary1 = false); +ALTER INDEX dummy_test_idx SET (option_ternary2 = Do_Not_Know_YET); ALTER INDEX dummy_test_idx SET (option_real = 3.2); ALTER INDEX dummy_test_idx SET (option_string_val = 'val2'); ALTER INDEX dummy_test_idx SET (option_string_null = NULL); @@ -40,6 +44,8 @@ SELECT unnest(reloptions) FROM pg_class WHERE relname = 'dummy_test_idx'; -- ALTER INDEX .. RESET ALTER INDEX dummy_test_idx RESET (option_int); ALTER INDEX dummy_test_idx RESET (option_bool); +ALTER INDEX dummy_test_idx RESET (option_ternary1); +ALTER INDEX dummy_test_idx RESET (option_ternary2); ALTER INDEX dummy_test_idx RESET (option_real); ALTER INDEX dummy_test_idx RESET (option_enum); ALTER INDEX dummy_test_idx RESET (option_string_val); @@ -60,6 +66,16 @@ ALTER INDEX dummy_test_idx SET (option_bool = 3.4); -- error ALTER INDEX dummy_test_idx SET (option_bool = 'val4'); -- error SELECT unnest(reloptions) FROM pg_class WHERE relname = 'dummy_test_idx'; ALTER INDEX dummy_test_idx RESET (option_bool); +-- Ternary +ALTER INDEX dummy_test_idx SET (option_ternary1 = 4); -- error +ALTER INDEX dummy_test_idx SET (option_ternary1 = 1); -- ok, as true +ALTER INDEX dummy_test_idx SET (option_ternary1 = 3.4); -- error +ALTER INDEX dummy_test_idx SET (option_ternary1 = 'val4'); -- error +ALTER INDEX dummy_test_idx SET (option_ternary1 = 'do_not_know_yet'); -- error. Valid for ternary2 not for ternary1 +ALTER INDEX dummy_test_idx SET (option_ternary2 = 'do_not_know_yet'); -- ok +SELECT unnest(reloptions) FROM pg_class WHERE relname = 'dummy_test_idx'; +ALTER INDEX dummy_test_idx RESET (option_ternary1); +ALTER INDEX dummy_test_idx RESET (option_ternary2); -- Float ALTER INDEX dummy_test_idx SET (option_real = 4); -- ok ALTER INDEX dummy_test_idx SET (option_real = true); -- error diff --git a/src/test/regress/expected/reloptions.out b/src/test/regress/expected/reloptions.out index 1c99f79ab0..6e65cd5c3d 100644 --- a/src/test/regress/expected/reloptions.out +++ b/src/test/regress/expected/reloptions.out @@ -98,7 +98,7 @@ SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; {fillfactor=13,autovacuum_enabled=false} (1 row) --- Tests for future (FIXME) ternary options +-- Tests for ternary options -- behave as boolean option: accept unassigned name and truncated value DROP TABLE reloptions_test; CREATE TABLE reloptions_test(i INT) WITH (vacuum_truncate); @@ -116,7 +116,7 @@ SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; {vacuum_truncate=fals} (1 row) --- preferred "true" alias is used when storing +-- preferred "true" alias is stored in pg_class DROP TABLE reloptions_test; CREATE TABLE reloptions_test(i INT) WITH (vacuum_index_cleanup=on); SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; diff --git a/src/test/regress/sql/reloptions.sql b/src/test/regress/sql/reloptions.sql index f5980dafcb..c99673db9e 100644 --- a/src/test/regress/sql/reloptions.sql +++ b/src/test/regress/sql/reloptions.sql @@ -59,7 +59,7 @@ UPDATE pg_class ALTER TABLE reloptions_test RESET (illegal_option); SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; --- Tests for future (FIXME) ternary options +-- Tests for ternary options -- behave as boolean option: accept unassigned name and truncated value DROP TABLE reloptions_test; @@ -70,7 +70,7 @@ DROP TABLE reloptions_test; CREATE TABLE reloptions_test(i INT) WITH (vacuum_truncate=FaLS); SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; --- preferred "true" alias is used when storing +-- preferred "true" alias is stored in pg_class DROP TABLE reloptions_test; CREATE TABLE reloptions_test(i INT) WITH (vacuum_index_cleanup=on); SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; -- 2.39.2 --nextPart5129932.5fSG56mABF-- --nextPart7913091.MhkbZ0Pkbq Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. 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* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 194+ messages in thread
* Do not lock tables in get_tables_to_repack @ 2026-06-16 07:34 =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> 0 siblings, 2 replies; 194+ messages in thread From: =?utf-8?B?Y2NhNTUwNw==?= @ 2026-06-16 07:34 UTC (permalink / raw) To: =?utf-8?B?cGdzcWwtaGFja2Vycw==?= <[email protected]> Hi hackers, When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). Thoughts? -- Regards, ChangAo Chen Attachments: [application/octet-stream] v1-0001-Do-not-lock-tables-in-get_tables_to_repack.patch (5.4K, ../../[email protected]/2-v1-0001-Do-not-lock-tables-in-get_tables_to_repack.patch) download | inline diff: From fa5c3073f2f41cf3c8ab7c9663b681e6140a4824 Mon Sep 17 00:00:00 2001 From: ChangAo Chen <[email protected]> Date: Tue, 16 Jun 2026 14:49:49 +0800 Subject: [PATCH v1] Do not lock tables in get_tables_to_repack(). When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index ec100e3eef5..6f25effeed2 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2159,22 +2159,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2182,7 +2169,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2191,10 +2177,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2218,45 +2201,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2269,7 +2227,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2347,15 +2305,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.34.1 ^ permalink raw reply [nested|flat] 194+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-06-27 19:56 Bharath Rupireddy <[email protected]> parent: =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> 1 sibling, 0 replies; 194+ messages in thread From: Bharath Rupireddy @ 2026-06-27 19:56 UTC (permalink / raw) To: cca5507 <[email protected]>; +Cc: pgsql-hackers <[email protected]>; Antonin Houska <[email protected]>; Alvaro Herrera <[email protected]> Hi, On Tue, Jun 16, 2026 at 12:35 AM cca5507 <[email protected]> wrote: > > Hi hackers, > > When doing a whole database repack, we build a list of repackable > tables and take a lock on them to prevent concurrent drops. But > concurrent drops can always happen after we build the list because > we process each table in a separate transaction. The > ConditionalLockRelationOid() also makes the default behavior like > SKIP_LOCKED, which is unexpected. > > To remove the locks, we need to make repack_is_permitted_for_relation() > handles concurrent drops correctly: it should not report an error > when failing to search the syscache in pg_class_aclcheck(). Use > pg_class_aclcheck_ext() instead to detect a concurrent drop. Also > check the return value of get_rel_name(). > > Thoughts? I don't have a strong opinion on fixing this for REPACK. For vacuum, we wanted to get consistent behavior across all modes of invoking it [1]. Whether to handle concurrent drops for REPACK depends on how long it spends scanning pg_index/pg_class in get_tables_to_repack. Also, vacuum is more commonly run database-wide (against all tables), and without field experience showing this is a real problem for REPACK, I'm not sure the fix is needed. That said, others may have a different take - adding the REPACK authors here for their input. [1] https://www.postgresql.org/message-id/CALj2ACUbhDFJWSwiyoUxXED2S2fr9Xis%3D08Rnjq53UzBE4FvzA%40mail.g... -- Bharath Rupireddy Amazon Web Services: https://aws.amazon.com ^ permalink raw reply [nested|flat] 194+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-07-07 16:53 Álvaro Herrera <[email protected]> parent: =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> 1 sibling, 1 reply; 194+ messages in thread From: Álvaro Herrera @ 2026-07-07 16:53 UTC (permalink / raw) To: cca5507 <[email protected]>; +Cc: pgsql-hackers <[email protected]> On 2026-Jun-16, cca5507 wrote: > Hi hackers, > > When doing a whole database repack, we build a list of repackable > tables and take a lock on them to prevent concurrent drops. But > concurrent drops can always happen after we build the list because > we process each table in a separate transaction. Not only that. We have actually three ways to obtain the list of tables to repack, and only one of these obtains the locks. So this code is internally inconsistent. I agree that we should do something like your patch. I wanted to be a little more defensive though; how about the attached? -- Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/ ^ permalink raw reply [nested|flat] 194+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-07-08 02:36 =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> parent: Álvaro Herrera <[email protected]> 0 siblings, 1 reply; 194+ messages in thread From: =?utf-8?B?Y2NhNTUwNw==?= @ 2026-07-08 02:36 UTC (permalink / raw) To: =?utf-8?B?w4FsdmFybyBIZXJyZXJh?= <[email protected]>; +Cc: =?utf-8?B?cGdzcWwtaGFja2Vycw==?= <[email protected]> > > Hi hackers, > > > > When doing a whole database repack, we build a list of repackable > > tables and take a lock on them to prevent concurrent drops. But > > concurrent drops can always happen after we build the list because > > we process each table in a separate transaction. > > Not only that. We have actually three ways to obtain the list of tables > to repack, and only one of these obtains the locks. So this code is > internally inconsistent. I agree that we should do something like your > patch. I wanted to be a little more defensive though; how about the > attached? - classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); + classtup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(index->indrelid)); Do we really need to copy it? We hold a refcount on it so it won't be freed until we release it. Otherwise LGTM. -- Regards, ChangAo Chen ^ permalink raw reply [nested|flat] 194+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-07-10 14:22 Álvaro Herrera <[email protected]> parent: =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> 0 siblings, 1 reply; 194+ messages in thread From: Álvaro Herrera @ 2026-07-10 14:22 UTC (permalink / raw) To: cca5507 <[email protected]>; +Cc: pgsql-hackers <[email protected]> On 2026-Jul-08, cca5507 wrote: > - classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); > + classtup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(index->indrelid)); > > Do we really need to copy it? We hold a refcount on it so it won't be freed > until we release it. Otherwise LGTM. Yeah, I guess it doesn't matter. I have removed the copy and updated some comments. I also realized that there are some places where we weren't dealing correctly with the possibility that the relation goes away, or is replaced with something different, so I added that too. While looking at it I also realized that get_tables_to_repack_partitioned is likewise not careful enough about it: we do IndexGetRelation(, false) which fails hard if the pg_index tuple cannot be found, which is the wrong thing to do. At the same time, it's annoying that half of the code that clearly belongs in that routine is actually in ExecRepack(). I moved that to where it rightfully belongs. (The only somewhat annoying thing is that we have to NULL-out the Relation pointer after returning; but that's not *too* bad IMO.) Any opinions on this? -- Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/ "No me acuerdo, pero no es cierto. No es cierto, y si fuera cierto, no me acuerdo." (Augusto Pinochet a una corte de justicia) ^ permalink raw reply [nested|flat] 194+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-07-10 16:03 Bharath Rupireddy <[email protected]> parent: Álvaro Herrera <[email protected]> 0 siblings, 1 reply; 194+ messages in thread From: Bharath Rupireddy @ 2026-07-10 16:03 UTC (permalink / raw) To: Álvaro Herrera <[email protected]>; +Cc: cca5507 <[email protected]>; pgsql-hackers <[email protected]> Hi, On Fri, Jul 10, 2026 at 7:22 AM Álvaro Herrera <[email protected]> wrote: > > On 2026-Jul-08, cca5507 wrote: > > > - classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); > > + classtup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(index->indrelid)); > > > > Do we really need to copy it? We hold a refcount on it so it won't be freed > > until we release it. Otherwise LGTM. Thanks for committing this. Here is my overall take. Even before this commit, a database-wide REPACK does not error on a concurrently dropped table. get_tables_to_repack takes a brief lock on each table before the ACL check, which blocks a concurrent drop while the list is being built. Later each table is re-opened under its lock and skipped if it is already gone. So the brief lock is not needed for correctness. What it does is let an unprivileged user lock relations it may not even be allowed to repack, including system catalogs, before we have checked its privileges. I am fine with removing the lock as the commit did. I would also like to tighten repack_is_permitted_for_relation so a caller that holds a lock still errors out on a missing relation instead of skipping it silently (https://www.postgresql.org/message-id/akPhEffRipH4isWF%40nathan). Attached as a follow-up patch. Please have a look. > Yeah, I guess it doesn't matter. I have removed the copy and updated > some comments. I also realized that there are some places where we > weren't dealing correctly with the possibility that the relation goes > away, or is replaced with something different, so I added that too. I agree that the SearchSysCacheCopy1 in v2-0002 adds no benefit. Since no lock is held on the relation, there is no point in copying the syscache tuple. > While looking at it I also realized that get_tables_to_repack_partitioned > is likewise not careful enough about it: we do IndexGetRelation(, false) > which fails hard if the pg_index tuple cannot be found, which is the > wrong thing to do. > > At the same time, it's annoying that half of the code that clearly > belongs in that routine is actually in ExecRepack(). I moved that to > where it rightfully belongs. (The only somewhat annoying thing is that > we have to NULL-out the Relation pointer after returning; but that's not > *too* bad IMO.) > > Any opinions on this? I will take a closer look at this in a bit. -- Bharath Rupireddy Amazon Web Services: https://aws.amazon.com Attachments: [application/octet-stream] v1-0001-Tighten-ACL-check-in-repack_is_permitted_for_rela.patch (5.1K, ../../CALj2ACX3pyuRS8++6L20cJUMRTf_qbbVp69J1btJ3y6=77e5gw@mail.gmail.com/2-v1-0001-Tighten-ACL-check-in-repack_is_permitted_for_rela.patch) download | inline diff: From 6729b2f14ed623a8b38f5a530b8c85c96bfd5b40 Mon Sep 17 00:00:00 2001 From: Bharath Rupireddy <[email protected]> Date: Fri, 10 Jul 2026 15:42:47 +0000 Subject: [PATCH v1] Tighten ACL check in repack_is_permitted_for_relation() Commit c71d43025d7 made repack_is_permitted_for_relation() use _ext() and skip a concurrently dropped relation silently. That is fine for the callers that hold no lock on the relation, but it is applied unconditionally, including where we may already hold a lock on the relation whose ACL is checked. In that case missing a relation is not fine, so this made the code more brittle: a missing relation there would indicate a bug and should error out rather than be skipped silently. Add a missing_ok flag so the silent skip is done only where no lock is held. Callers that hold a lock pass false and still error out on a missing relation. --- src/backend/commands/repack.c | 38 ++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 12 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index 02883fe34a4..b09be65da3b 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -172,8 +172,8 @@ static List *get_tables_to_repack(RepackCommand cmd, bool usingindex, static List *get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, bool rel_is_index, MemoryContext permcxt); -static bool repack_is_permitted_for_relation(RepackCommand cmd, - Oid relid, Oid userid); +static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, + Oid userid, bool missing_ok); static void apply_concurrent_changes(BufFile *file, ChangeContext *chgcxt); static void apply_concurrent_insert(Relation rel, TupleTableSlot *slot, @@ -724,7 +724,7 @@ cluster_rel_recheck(RepackCommand cmd, Relation OldHeap, Oid indexOid, Assert(CheckRelationLockedByMe(OldHeap, lmode, false)); /* Check that the user still has privileges for the relation */ - if (!repack_is_permitted_for_relation(cmd, tableOid, userid)) + if (!repack_is_permitted_for_relation(cmd, tableOid, userid, false)) { relation_close(OldHeap, lmode); return false; @@ -2198,7 +2198,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, - GetUserId())) + GetUserId(), true)) continue; /* Use a permanent memory context for the result list */ @@ -2235,7 +2235,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, - GetUserId())) + GetUserId(), true)) continue; /* Use a permanent memory context for the result list */ @@ -2304,7 +2304,7 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, * leaf partition despite having them on the partitioned table. Skip * if so. */ - if (!repack_is_permitted_for_relation(cmd, table_oid, GetUserId())) + if (!repack_is_permitted_for_relation(cmd, table_oid, GetUserId(), true)) continue; /* Use a permanent memory context for the result list */ @@ -2321,16 +2321,21 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, /* - * Return whether userid has privileges to execute REPACK on relid. + * Check whether the passed-in user has privileges to execute REPACK on the + * relation. * - * Caller may not have a lock on the relation, so it could have been - * dropped concurrently. In that case, silently return false. + * missing_ok should be passed only by callers that hold no lock on the + * relation, where a concurrent drop is possible and fine to skip. A caller + * that holds a lock must not pass it: there a missing relation would indicate + * a bug and should error out rather than be silently skipped. * * If the relation does exist but the user doesn't have the required - * privs, emit a WARNING and return false. Otherwise, return true. + * privileges, emit a WARNING and return false to let the caller + * decide what to do with this relation. */ static bool -repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) +repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid, + bool missing_ok) { bool is_missing = false; AclResult result; @@ -2338,9 +2343,18 @@ repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - result = pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing); + result = pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, + missing_ok ? &is_missing : NULL); + + /* + * If the relation was concurrently dropped, nothing to do. Note that this + * is only reachable when the caller specified missing_ok. + */ if (is_missing) + { + Assert(missing_ok); return false; + } if (result == ACLCHECK_OK) return true; -- 2.47.3 ^ permalink raw reply [nested|flat] 194+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-07-10 17:34 Bharath Rupireddy <[email protected]> parent: Bharath Rupireddy <[email protected]> 0 siblings, 1 reply; 194+ messages in thread From: Bharath Rupireddy @ 2026-07-10 17:34 UTC (permalink / raw) To: Álvaro Herrera <[email protected]>; +Cc: cca5507 <[email protected]>; pgsql-hackers <[email protected]> Hi, On Fri, Jul 10, 2026 at 9:03 AM Bharath Rupireddy <[email protected]> wrote: > > > While looking at it I also realized that get_tables_to_repack_partitioned > > is likewise not careful enough about it: we do IndexGetRelation(, false) > > which fails hard if the pg_index tuple cannot be found, which is the > > wrong thing to do. Agreed. For a single-level partitioned table, dropping a leaf blocks on the parent's AccessExclusiveLock, which REPACK holds, so the leaf can't go away mid-build. But for a multi-level table, REPACK holds a lock only on the top parent, so a lower-level leaf whose immediate parent is an intermediate table isn't protected and can be dropped concurrently. So IndexGetRelation(, false) failing hard there is indeed the wrong thing. > > At the same time, it's annoying that half of the code that clearly > > belongs in that routine is actually in ExecRepack(). I moved that to > > where it rightfully belongs. +1, that's a good cleanup. That code clearly belongs in get_tables_to_repack_partitioned(). >> (The only somewhat annoying thing is that > > we have to NULL-out the Relation pointer after returning; but that's not > > *too* bad IMO.) That's fine. We already NULL out rel after get_tables_to_repack_partitioned() today, so the patch isn't adding anything new there. Relying on a non-NULL return from process_single_relation() to mean partitioned table is a little indirect on first read, but the comments explains it well, and I wouldn't complicate the code to avoid it. > > Any opinions on this? > > I will take a closer look at this in a bit. Patch looks good to me. One nit: + table_oid = IndexGetRelation(child_oid, true); + if (!OidIsValid(table_oid)) + continue; How about a short comment on why this is needed even with a lock on the parent, since that lock doesn't cover lower-level leaves in a multi-level partition tree? -- Bharath Rupireddy Amazon Web Services: https://aws.amazon.com ^ permalink raw reply [nested|flat] 194+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-07-11 14:50 =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> parent: Bharath Rupireddy <[email protected]> 0 siblings, 1 reply; 194+ messages in thread From: =?utf-8?B?Y2NhNTUwNw==?= @ 2026-07-11 14:50 UTC (permalink / raw) To: =?utf-8?B?QmhhcmF0aCBSdXBpcmVkZHk=?= <[email protected]>; =?utf-8?B?w4FsdmFybyBIZXJyZXJh?= <[email protected]>; +Cc: =?utf-8?B?cGdzcWwtaGFja2Vycw==?= <[email protected]> > > > Any opinions on this? > > > > I will take a closer look at this in a bit. > > Patch looks good to me. One nit: > > + table_oid = IndexGetRelation(child_oid, true); > + if (!OidIsValid(table_oid)) > + continue; > > How about a short comment on why this is needed even with a lock on > the parent, since that lock doesn't cover lower-level leaves in a > multi-level partition tree? I think it's worth a comment, too. Patch LGTM. -- Regards, ChangAo Chen ^ permalink raw reply [nested|flat] 194+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-07-20 10:19 Álvaro Herrera <[email protected]> parent: =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> 0 siblings, 0 replies; 194+ messages in thread From: Álvaro Herrera @ 2026-07-20 10:19 UTC (permalink / raw) To: cca5507 <[email protected]>; +Cc: Bharath Rupireddy <[email protected]>; pgsql-hackers <[email protected]> On 2026-Jul-11, cca5507 wrote: > Bharath Rupireddy wrote: > > + table_oid = IndexGetRelation(child_oid, true); > > + if (!OidIsValid(table_oid)) > > + continue; > > > > How about a short comment on why this is needed even with a lock on > > the parent, since that lock doesn't cover lower-level leaves in a > > multi-level partition tree? > > I think it's worth a comment, too. Patch LGTM. Thanks, added that and pushed. -- Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/ "Puedes vivir sólo una vez, pero si lo haces bien, una vez es suficiente" ^ permalink raw reply [nested|flat] 194+ messages in thread
end of thread, other threads:[~2026-07-20 10:19 UTC | newest] Thread overview: 194+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2025-09-04 16:28 [PATCH v2 4/4] Extra tests Nikolay Shaplov <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 07:34 Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> 2026-06-27 19:56 ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]> 2026-07-07 16:53 ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]> 2026-07-08 02:36 ` Re: Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> 2026-07-10 14:22 ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]> 2026-07-10 16:03 ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]> 2026-07-10 17:34 ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]> 2026-07-11 14:50 ` Re: Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> 2026-07-20 10:19 ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
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