Prevent asynchronous execution of direct foreign-table modifications.

Commits 27e1f1456 and 86dc90056, which were independently discussed,
cause a crash when executing an inherited foreign UPDATE/DELETE query
with asynchronous execution enabled, where children of an Append node
that is the direct/indirect child of the ModifyTable node are rewritten
so as to modify foreign tables directly by postgresPlanDirectModify();
as in that case the direct modifications are executed asynchronously,
which is not currently supported by asynchronous execution.  Fix by
disabling asynchronous execution of the direct modifications in that
function.

Author: Etsuro Fujita
Reviewed-by: Amit Langote
Discussion: https://postgr.es/m/CAPmGK158e9sJOfuWxfn%2B0ynrspXQU3JhNjSCbaoeSzMvnga%2Bbw%40mail.gmail.com

1 files changed, 8 insertions, 0 deletions

diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index 53adfe2abc8..78379bdea5b 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -3237,6 +3237,14 @@ DROP TABLE base_tbl4;
 RESET enable_mergejoin;
 RESET enable_hashjoin;
 
+-- Test that UPDATE/DELETE with inherited target works with async_capable enabled
+EXPLAIN (VERBOSE, COSTS OFF)
+UPDATE async_pt SET c = c || c WHERE b = 0 RETURNING *;
+UPDATE async_pt SET c = c || c WHERE b = 0 RETURNING *;
+EXPLAIN (VERBOSE, COSTS OFF)
+DELETE FROM async_pt WHERE b = 0 RETURNING *;
+DELETE FROM async_pt WHERE b = 0 RETURNING *;
+
 -- Check EXPLAIN ANALYZE for a query that scans empty partitions asynchronously
 DELETE FROM async_p1;
 DELETE FROM async_p2;