From a4f7d33a904fcd4da7a12d249416dd2c5c5f2c1c Mon Sep 17 00:00:00 2001 From: Dean Rasheed Date: Thu, 9 Nov 2023 11:23:42 +0000 Subject: Fix AFTER ROW trigger execution in MERGE cross-partition update. When executing a MERGE UPDATE action, if the UPDATE is turned into a cross-partition DELETE then INSERT, do not attempt to invoke AFTER UPDATE ROW triggers, or any of the other post-update actions in ExecUpdateEpilogue(). For consistency with a plain UPDATE command, such triggers should not be fired (and typically fail anyway), and similarly, other post-update actions, such as WCO/RLS checks should not be executed, and might also lead to unexpected failures. Therefore, as with ExecUpdate(), make ExecMergeMatched() return immediately if ExecUpdateAct() reports that a cross-partition update was done, to be sure that no further processing is done for that tuple. Back-patch to v15, where MERGE was introduced. Discussion: https://postgr.es/m/CAEZATCWjBgagyNZs02vgDF0DvASYj-iHTFtXG2-nP3orZhmtcw%40mail.gmail.com --- src/backend/executor/nodeModifyTable.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'src/backend/executor/nodeModifyTable.c') diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c index 299c2c75be8..b16fbe9e22a 100644 --- a/src/backend/executor/nodeModifyTable.c +++ b/src/backend/executor/nodeModifyTable.c @@ -2899,6 +2899,22 @@ lmerge_matched: } result = ExecUpdateAct(context, resultRelInfo, tupleid, NULL, newslot, false, &updateCxt); + + /* + * As in ExecUpdate(), if ExecUpdateAct() reports that a + * cross-partition update was done, then there's nothing else + * for us to do --- the UPDATE has been turned into a DELETE + * and an INSERT, and we must not perform any of the usual + * post-update tasks. + */ + if (updateCxt.crossPartUpdate) + { + mtstate->mt_merge_updated += 1; + if (canSetTag) + (estate->es_processed)++; + return true; + } + if (result == TM_Ok && updateCxt.updated) { ExecUpdateEpilogue(context, &updateCxt, resultRelInfo, -- cgit v1.2.3