From 30a35bca3f9306f87ca8db095ddac2ba62156934 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 7 Jul 2021 15:21:25 -0400 Subject: Fix crash in postgres_fdw for provably-empty remote UPDATE/DELETE. In 86dc90056, I'd written find_modifytable_subplan with the assumption that if the immediate child of a ModifyTable is a Result, it must be a projecting Result with a subplan. However, if the UPDATE or DELETE has a provably-constant-false WHERE clause, that's not so: we'll generate a dummy subplan with a childless Result. Add the missing null-check so we don't crash on such cases. Per report from Alexander Pyhalov. Discussion: https://postgr.es/m/b9a6f53549456b2f3e2fd150dcd79d72@postgrespro.ru --- contrib/postgres_fdw/expected/postgres_fdw.out | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'contrib/postgres_fdw/expected/postgres_fdw.out') diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out index b510322c4ea..b8561d6a3c4 100644 --- a/contrib/postgres_fdw/expected/postgres_fdw.out +++ b/contrib/postgres_fdw/expected/postgres_fdw.out @@ -6853,6 +6853,26 @@ DROP TRIGGER trig_row_before ON rem1; DROP TRIGGER trig_row_after ON rem1; DROP TRIGGER trig_local_before ON loc1; -- Test direct foreign table modification functionality +EXPLAIN (verbose, costs off) +DELETE FROM rem1; -- can be pushed down + QUERY PLAN +--------------------------------------------- + Delete on public.rem1 + -> Foreign Delete on public.rem1 + Remote SQL: DELETE FROM public.loc1 +(3 rows) + +EXPLAIN (verbose, costs off) +DELETE FROM rem1 WHERE false; -- currently can't be pushed down + QUERY PLAN +------------------------------------------------------- + Delete on public.rem1 + Remote SQL: DELETE FROM public.loc1 WHERE ctid = $1 + -> Result + Output: ctid + One-Time Filter: false +(5 rows) + -- Test with statement-level triggers CREATE TRIGGER trig_stmt_before BEFORE DELETE OR INSERT OR UPDATE ON rem1 -- cgit v1.2.3