From d732148398a6e406170383ab21960ac373cd1316 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Thu, 2 Jan 2020 17:04:24 -0300 Subject: [PATCH] Fix cloning of row triggers to sub-partitions When row triggers exist in partitioned partitions that are not either part of FKs or deferred unique constraints, they are not correctly cloned to their partitions. That's because they are marked "internal", and those are purposefully skipped when doing the clone triggers dance. Fix by relaxing the condition on which internal triggers are skipped. Amit Langote initially diagnosed the problem and proposed a fix, but I used a different approach. Reported-by: Petr Fedorov Discussion: https://postgr.es/m/6b3f0646-ba8c-b3a9-c62d-1c6651a1920f@phystech.edu --- src/backend/commands/tablecmds.c | 65 +++++++++++++++++++++++++- src/test/regress/expected/triggers.out | 36 ++++++++------ src/test/regress/sql/triggers.sql | 4 ++ 3 files changed, 90 insertions(+), 15 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index ea978ce699..d3e0f88243 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -15988,6 +15988,54 @@ out: MemoryContextDelete(cxt); } +/* + * isPartitionTrigger + * Subroutine for CloneRowTriggersToPartition: determine whether + * the given trigger has been cloned from another one. + * + * We use pg_depend as a proxy for this, since we don't have any direct + * evidence. 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 +isPartitionTrigger(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 @@ -16028,8 +16076,21 @@ 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 || + !isPartitionTrigger(trigForm->oid))) continue; /* diff --git a/src/test/regress/expected/triggers.out b/src/test/regress/expected/triggers.out index 1e4053ceed..b91fbd0648 100644 --- a/src/test/regress/expected/triggers.out +++ b/src/test/regress/expected/triggers.out @@ -1981,15 +1981,22 @@ create trigger trg1 after insert on trigpart for each row execute procedure trig create table trigpart2 partition of trigpart for values from (1000) to (2000); create table trigpart3 (like trigpart); alter table trigpart attach partition trigpart3 for values from (2000) to (3000); +create table trigpart4 partition of trigpart for values from (3000) to (4000) partition by range (a); +create table trigpart41 partition of trigpart4 for values from (3000) to (3500); +create table trigpart42 (like trigpart); +alter table trigpart4 attach partition trigpart42 for values from (3500) to (4000); select tgrelid::regclass, tgname, tgfoid::regproc from pg_trigger where tgrelid::regclass::text like 'trigpart%' order by tgrelid::regclass::text; - tgrelid | tgname | tgfoid ------------+--------+----------------- - trigpart | trg1 | trigger_nothing - trigpart1 | trg1 | trigger_nothing - trigpart2 | trg1 | trigger_nothing - trigpart3 | trg1 | trigger_nothing -(4 rows) + tgrelid | tgname | tgfoid +------------+--------+----------------- + trigpart | trg1 | trigger_nothing + trigpart1 | trg1 | trigger_nothing + trigpart2 | trg1 | trigger_nothing + trigpart3 | trg1 | trigger_nothing + trigpart4 | trg1 | trigger_nothing + trigpart41 | trg1 | trigger_nothing + trigpart42 | trg1 | trigger_nothing +(7 rows) drop trigger trg1 on trigpart1; -- fail ERROR: cannot drop trigger trg1 on table trigpart1 because trigger trg1 on table trigpart requires it @@ -2003,12 +2010,15 @@ HINT: You can drop trigger trg1 on table trigpart instead. drop table trigpart2; -- ok, trigger should be gone in that partition select tgrelid::regclass, tgname, tgfoid::regproc from pg_trigger where tgrelid::regclass::text like 'trigpart%' order by tgrelid::regclass::text; - tgrelid | tgname | tgfoid ------------+--------+----------------- - trigpart | trg1 | trigger_nothing - trigpart1 | trg1 | trigger_nothing - trigpart3 | trg1 | trigger_nothing -(3 rows) + tgrelid | tgname | tgfoid +------------+--------+----------------- + trigpart | trg1 | trigger_nothing + trigpart1 | trg1 | trigger_nothing + trigpart3 | trg1 | trigger_nothing + trigpart4 | trg1 | trigger_nothing + trigpart41 | trg1 | trigger_nothing + trigpart42 | trg1 | trigger_nothing +(6 rows) drop trigger trg1 on trigpart; -- ok, all gone select tgrelid::regclass, tgname, tgfoid::regproc from pg_trigger diff --git a/src/test/regress/sql/triggers.sql b/src/test/regress/sql/triggers.sql index c21b6c124e..7cd835449c 100644 --- a/src/test/regress/sql/triggers.sql +++ b/src/test/regress/sql/triggers.sql @@ -1366,6 +1366,10 @@ create trigger trg1 after insert on trigpart for each row execute procedure trig create table trigpart2 partition of trigpart for values from (1000) to (2000); create table trigpart3 (like trigpart); alter table trigpart attach partition trigpart3 for values from (2000) to (3000); +create table trigpart4 partition of trigpart for values from (3000) to (4000) partition by range (a); +create table trigpart41 partition of trigpart4 for values from (3000) to (3500); +create table trigpart42 (like trigpart); +alter table trigpart4 attach partition trigpart42 for values from (3500) to (4000); select tgrelid::regclass, tgname, tgfoid::regproc from pg_trigger where tgrelid::regclass::text like 'trigpart%' order by tgrelid::regclass::text; drop trigger trg1 on trigpart1; -- fail