From 1af46b05c7b0760e3d0a782a869b8e961cc6f96d Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Tue, 31 Dec 2019 16:39:41 -0300 Subject: [PATCH 2/2] Fix trigger cloning --- src/backend/commands/tablecmds.c | 64 +++++++++++++++++++++++++++++++- 1 file changed, 62 insertions(+), 2 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 5b882f80bf..7d0b49e9a4 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -15930,6 +15930,53 @@ out: MemoryContextDelete(cxt); } +/* + * doesTriggerDependOnAnotherTrigger + * Checks pg_depend for what the name says + * + * This is an ugly hack to cope with a catalog deficiency. + * Keep away from children. Do not stare with naked eyes. Do not propagate. + */ +static bool +doesTriggerDependOnAnotherTrigger(Oid trigger_oid) +{ + Relation pg_depend; + ScanKeyData key[2]; + SysScanDesc scan; + HeapTuple tup; + bool found = false; + + pg_depend = table_open(DependRelationId, AccessShareLock); + + ScanKeyInit(&key[0], Anum_pg_depend_classid, + BTEqualStrategyNumber, + F_OIDEQ, + ObjectIdGetDatum(TriggerRelationId)); + ScanKeyInit(&key[1], Anum_pg_depend_objid, + BTEqualStrategyNumber, + F_OIDEQ, + ObjectIdGetDatum(trigger_oid)); + + scan = systable_beginscan(pg_depend, DependDependerIndexId, + true, NULL, 2, key); + while ((tup = systable_getnext(scan)) != NULL) + { + Form_pg_depend dep = (Form_pg_depend) GETSTRUCT(tup); + + if (dep->refclassid == TriggerRelationId) + { + found = true; + break; + } + } + + systable_endscan(scan); + table_close(pg_depend, AccessShareLock); + + return found; +} + + /* * CloneRowTriggersToPartition * subroutine for ATExecAttachPartition/DefineRelation to create row @@ -15970,8 +16017,21 @@ CloneRowTriggersToPartition(Relation parent, Relation partition) if (!TRIGGER_FOR_ROW(trigForm->tgtype)) continue; - /* We don't clone internal triggers, either */ - if (trigForm->tgisinternal) + /* + * Internal triggers require careful examination. Ideally, we don't + * clone them. + * + * However, if our parent is a partitioned relation, there might be + * internal triggers that need cloning. In that case, we must + * skip clone it if the trigger on parent depends on another trigger. + * + * Note we dare not verify that the other trigger belongs to an + * ancestor relation of our parent, because that creates deadlock + * opportunities. + */ + if (trigForm->tgisinternal && + (!parent->rd_rel->relispartition || + !doesTriggerDependOnAnotherTrigger(trigForm->oid))) continue; /* -- 2.20.1