From d57d212305abd2cfb15c6c61f98e503e1a736ab2 Mon Sep 17 00:00:00 2001 From: Jim Jones Date: Tue, 24 Mar 2026 13:50:26 +0100 Subject: [PATCH v1] Skip other sessions' temp tables in REPACK, CLUSTER, and VACUUM FULL get_tables_to_repack() was including other sessions' temporary tables in the work list, causing REPACK and CLUSTER (without arguments) to attempt to acquire AccessExclusiveLock on them, potentially blocking for an extended time. Fix by skipping other-session temp tables early in get_tables_to_repack(), before they are added to the list. Because an AccessShareLock has already been acquired per relation at that point, release it before continuing. Similarly, get_all_vacuum_rels() suffered from the same problem for VACUUM FULL. Since no per-relation lock is held during list-building there, a plain skip suffices. --- src/backend/commands/cluster.c | 15 +++++++++++++++ src/backend/commands/vacuum.c | 5 +++++ 2 files changed, 20 insertions(+) diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c index 09066db095..f701d426dd 100644 --- a/src/backend/commands/cluster.c +++ b/src/backend/commands/cluster.c @@ -1699,6 +1699,13 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) continue; } + /* Skip temp relations belonging to other sessions */ + if (isOtherTempNamespace(get_rel_namespace(index->indrelid))) + { + UnlockRelationOid(index->indrelid, AccessShareLock); + continue; + } + /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) @@ -1753,6 +1760,14 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) continue; } + /* Skip temp relations belonging to other sessions */ + if (class->relpersistence == RELPERSISTENCE_TEMP && + isOtherTempNamespace(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())) diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c index bce3a2daa2..642f4fee1c 100644 --- a/src/backend/commands/vacuum.c +++ b/src/backend/commands/vacuum.c @@ -1062,6 +1062,11 @@ get_all_vacuum_rels(MemoryContext vac_context, int options) classForm->relkind != RELKIND_PARTITIONED_TABLE) continue; + /* Skip temp relations belonging to other sessions */ + if (classForm->relpersistence == RELPERSISTENCE_TEMP && + isOtherTempNamespace(classForm->relnamespace)) + continue; + /* check permissions of relation */ if (!vacuum_is_permitted_for_relation(relid, classForm, options)) continue; -- 2.43.0