From cb90de1aac18f8d9d89af8a3c2286aa0691c8214 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Sun, 10 Feb 2019 10:00:11 -0300 Subject: [PATCH] Fix trigger drop procedure After commit 123cc697a8eb, we remove redundant FK action triggers during partition ATTACH by merely deleting the catalog tuple, but that's wrong: it should use performDeletion() instead. Repair, and make the comments more explicit. Per code review from Tom Lane. Discussion: https://postgr.es/m/18885.1549642539@sss.pgh.pa.us --- src/backend/commands/tablecmds.c | 33 +++++++++++++++++++++++--------- 1 file changed, 24 insertions(+), 9 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 35a9ade0590..b66d194b80d 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -7919,10 +7919,12 @@ CloneFkReferencing(Relation pg_constraint, Relation parentRel, ReleaseSysCache(partcontup); /* - * Looks good! Attach this constraint. Note that the action - * triggers are no longer needed, so remove them. We identify - * them because they have our constraint OID, as well as being - * on the referenced rel. + * Looks good! Attach this constraint. The action triggers in + * the new partition become redundant -- the parent table already + * has equivalent ones, and those will be able to reach the + * partition. Remove the ones in the partition. We identify them + * because they have our constraint OID, as well as being on the + * referenced rel. */ trigrel = heap_open(TriggerRelationId, RowExclusiveLock); ScanKeyInit(&key, @@ -7935,17 +7937,30 @@ CloneFkReferencing(Relation pg_constraint, Relation parentRel, while ((trigtup = systable_getnext(scan)) != NULL) { Form_pg_trigger trgform = (Form_pg_trigger) GETSTRUCT(trigtup); + ObjectAddress trigger; if (trgform->tgconstrrelid != fk->conrelid) continue; if (trgform->tgrelid != fk->confrelid) continue; - deleteDependencyRecordsForClass(TriggerRelationId, - trgform->oid, - ConstraintRelationId, - DEPENDENCY_INTERNAL); - CatalogTupleDelete(trigrel, &trigtup->t_self); + /* + * The constraint is originally set up to contain this trigger + * as an implementation object, so there's a dependency record + * that links the two; however, since the trigger is no longer + * needed, we remove the dependency link in order to be able + * to drop the trigger while keeping the constraint intact. + */ + deleteDependencyRecordsFor(TriggerRelationId, + trgform->oid, + false); + /* make dependency deletion visible to performDeletion */ + CommandCounterIncrement(); + ObjectAddressSet(trigger, TriggerRelationId, + trgform->oid); + performDeletion(&trigger, DROP_RESTRICT, 0); + /* make trigger drop visible, in case the loop iterates */ + CommandCounterIncrement(); } systable_endscan(scan);