From 547e454cbc8f8896b535cf2debd61b2c5701d8c0 Mon Sep 17 00:00:00 2001 From: Etsuro Fujita Date: Tue, 10 Dec 2019 18:00:31 +0900 Subject: [PATCH] Fix handling of multiple AFTER ROW triggers on a foreign table. AfterTriggerExecute() retrieves a fresh tuple or pair of tuples from a tuplestore and then stores the tuple(s) in the passed-in slot(s) if AFTER_TRIGGER_FDW_FETCH, while it uses the most-recently-retrieved tuple(s) stored in the slot(s) if AFTER_TRIGGER_FDW_REUSE. This was done correctly before 12, but commit ff11e7f4b broke it by mistakenly clearing the tuple(s) stored in the slot(s) in that function, leading to an assertion failure as reported in bug #16139 from Alexander Lakhin. Also, fix some other issues with the aforementioned commit in passing: * For tg_newslot, which is a slot added to the TriggerData struct by the commit to store new updated tuples, it didn't ensure the slot was NULL if there was no such tuple. * The commit failed to update the documentation about the trigger interface. Author: Etsuro Fujita Backpatch-through: 12 Discussion: https://postgr.es/m/16139-94f9ccf0db6119ec%40postgresql.org --- .../postgres_fdw/expected/postgres_fdw.out | 32 ++++++++++++++- contrib/postgres_fdw/sql/postgres_fdw.sql | 17 ++++++++ doc/src/sgml/trigger.sgml | 16 ++++---- src/backend/commands/trigger.c | 40 ++++++++++++------- 4 files changed, 81 insertions(+), 24 deletions(-) diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out index f0c842a607..5c135becf1 100644 --- a/contrib/postgres_fdw/expected/postgres_fdw.out +++ b/contrib/postgres_fdw/expected/postgres_fdw.out @@ -6459,6 +6459,36 @@ DROP TRIGGER trig_row_after ON rem1; DROP TRIGGER trig_stmt_before ON rem1; DROP TRIGGER trig_stmt_after ON rem1; DELETE from rem1; +-- Test multiple AFTER ROW triggers on a foreign table +CREATE TRIGGER trig_row_after1 +AFTER INSERT OR UPDATE OR DELETE ON rem1 +FOR EACH ROW EXECUTE PROCEDURE trigger_data(23,'skidoo'); +CREATE TRIGGER trig_row_after2 +AFTER INSERT OR UPDATE OR DELETE ON rem1 +FOR EACH ROW EXECUTE PROCEDURE trigger_data(23,'skidoo'); +insert into rem1 values(1,'insert'); +NOTICE: trig_row_after1(23, skidoo) AFTER ROW INSERT ON rem1 +NOTICE: NEW: (1,insert) +NOTICE: trig_row_after2(23, skidoo) AFTER ROW INSERT ON rem1 +NOTICE: NEW: (1,insert) +update rem1 set f2 = 'update' where f1 = 1; +NOTICE: trig_row_after1(23, skidoo) AFTER ROW UPDATE ON rem1 +NOTICE: OLD: (1,insert),NEW: (1,update) +NOTICE: trig_row_after2(23, skidoo) AFTER ROW UPDATE ON rem1 +NOTICE: OLD: (1,insert),NEW: (1,update) +update rem1 set f2 = f2 || f2; +NOTICE: trig_row_after1(23, skidoo) AFTER ROW UPDATE ON rem1 +NOTICE: OLD: (1,update),NEW: (1,updateupdate) +NOTICE: trig_row_after2(23, skidoo) AFTER ROW UPDATE ON rem1 +NOTICE: OLD: (1,update),NEW: (1,updateupdate) +delete from rem1; +NOTICE: trig_row_after1(23, skidoo) AFTER ROW DELETE ON rem1 +NOTICE: OLD: (1,updateupdate) +NOTICE: trig_row_after2(23, skidoo) AFTER ROW DELETE ON rem1 +NOTICE: OLD: (1,updateupdate) +-- cleanup +DROP TRIGGER trig_row_after1 ON rem1; +DROP TRIGGER trig_row_after2 ON rem1; -- Test WHEN conditions CREATE TRIGGER trig_row_before_insupd BEFORE INSERT OR UPDATE ON rem1 @@ -6689,7 +6719,7 @@ NOTICE: trig_row_after(23, skidoo) AFTER ROW INSERT ON rem1 NOTICE: NEW: (13,"test triggered !") ctid -------- - (0,29) + (0,32) (1 row) -- cleanup diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql index 630b803e26..0404222b7a 100644 --- a/contrib/postgres_fdw/sql/postgres_fdw.sql +++ b/contrib/postgres_fdw/sql/postgres_fdw.sql @@ -1485,6 +1485,23 @@ DROP TRIGGER trig_stmt_after ON rem1; DELETE from rem1; +-- Test multiple AFTER ROW triggers on a foreign table +CREATE TRIGGER trig_row_after1 +AFTER INSERT OR UPDATE OR DELETE ON rem1 +FOR EACH ROW EXECUTE PROCEDURE trigger_data(23,'skidoo'); + +CREATE TRIGGER trig_row_after2 +AFTER INSERT OR UPDATE OR DELETE ON rem1 +FOR EACH ROW EXECUTE PROCEDURE trigger_data(23,'skidoo'); + +insert into rem1 values(1,'insert'); +update rem1 set f2 = 'update' where f1 = 1; +update rem1 set f2 = f2 || f2; +delete from rem1; + +-- cleanup +DROP TRIGGER trig_row_after1 ON rem1; +DROP TRIGGER trig_row_after2 ON rem1; -- Test WHEN conditions diff --git a/doc/src/sgml/trigger.sgml b/doc/src/sgml/trigger.sgml index f62f420c19..ba94acad69 100644 --- a/doc/src/sgml/trigger.sgml +++ b/doc/src/sgml/trigger.sgml @@ -511,8 +511,8 @@ typedef struct TriggerData HeapTuple tg_trigtuple; HeapTuple tg_newtuple; Trigger *tg_trigger; - Buffer tg_trigtuplebuf; - Buffer tg_newtuplebuf; + TupleTableSlot *tg_trigslot; + TupleTableSlot *tg_newslot; Tuplestorestate *tg_oldtable; Tuplestorestate *tg_newtable; } TriggerData; @@ -714,21 +714,21 @@ typedef struct Trigger - tg_trigtuplebuf + tg_trigslot - The buffer containing tg_trigtuple, or InvalidBuffer if there - is no such tuple or it is not stored in a disk buffer. + The slot containing tg_trigtuple, + or a NULL pointer if there is no such tuple. - tg_newtuplebuf + tg_newslot - The buffer containing tg_newtuple, or InvalidBuffer if there - is no such tuple or it is not stored in a disk buffer. + The slot containing tg_newtuple, + or a NULL pointer if there is no such tuple. diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c index 21719c0bb1..063d77eea2 100644 --- a/src/backend/commands/trigger.c +++ b/src/backend/commands/trigger.c @@ -4258,12 +4258,17 @@ AfterTriggerExecute(EState *estate, LocTriggerData.tg_trigtuple = ExecFetchSlotHeapTuple(trig_tuple_slot1, true, &should_free_trig); - LocTriggerData.tg_newslot = trig_tuple_slot2; - LocTriggerData.tg_newtuple = - ((evtshared->ats_event & TRIGGER_EVENT_OPMASK) == - TRIGGER_EVENT_UPDATE) ? - ExecFetchSlotHeapTuple(trig_tuple_slot2, true, &should_free_new) : NULL; - + if ((evtshared->ats_event & TRIGGER_EVENT_OPMASK) == + TRIGGER_EVENT_UPDATE) + { + LocTriggerData.tg_newslot = trig_tuple_slot2; + LocTriggerData.tg_newtuple = + ExecFetchSlotHeapTuple(trig_tuple_slot2, true, &should_free_new); + } + else + { + LocTriggerData.tg_newtuple = NULL; + } break; default: @@ -4358,10 +4363,14 @@ AfterTriggerExecute(EState *estate, if (should_free_new) heap_freetuple(LocTriggerData.tg_newtuple); - if (LocTriggerData.tg_trigslot) - ExecClearTuple(LocTriggerData.tg_trigslot); - if (LocTriggerData.tg_newslot) - ExecClearTuple(LocTriggerData.tg_newslot); + /* don't clear slots' contents if foreign table */ + if (trig_tuple_slot1 == NULL) + { + if (LocTriggerData.tg_trigslot) + ExecClearTuple(LocTriggerData.tg_trigslot); + if (LocTriggerData.tg_newslot) + ExecClearTuple(LocTriggerData.tg_newslot); + } /* * If doing EXPLAIN ANALYZE, stop charging time to this trigger, and count @@ -4515,13 +4524,14 @@ afterTriggerInvokeEvents(AfterTriggerEventList *events, trigdesc = rInfo->ri_TrigDesc; finfo = rInfo->ri_TrigFunctions; instr = rInfo->ri_TrigInstrument; + if (slot1 != NULL) + { + ExecDropSingleTupleTableSlot(slot1); + ExecDropSingleTupleTableSlot(slot2); + slot1 = slot2 = NULL; + } if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) { - if (slot1 != NULL) - { - ExecDropSingleTupleTableSlot(slot1); - ExecDropSingleTupleTableSlot(slot2); - } slot1 = MakeSingleTupleTableSlot(rel->rd_att, &TTSOpsMinimalTuple); slot2 = MakeSingleTupleTableSlot(rel->rd_att,