On 26/6/2025 07:40, Michael Paquier wrote:
Anyway, it seems to me that we may need to do something here before
the release. Note that if the consensus is "you should update your
module and not rely on the past behavior", I'm OK with that. I just
wanted to raise the issue before this goes GA. And well, I have a
pretty big pool of users that rely on this module, so..
Thanks for the report and detailed explanation!
Before diving into the pg_hint_plan code, I wonder why you don't have
similar issues with the remove_useless_joins. We intentionally designed
SJE coupled with the left-join removal feature to avoid such type of
complaints:
CREATE TABLE test (x integer PRIMARY KEY);
EXPLAIN (COSTS OFF)
SELECT t1.* FROM test t1 LEFT JOIN test t2 ON (t1.x=t2.x);
/*
QUERY PLAN
---------------------
Seq Scan on test t1
(1 row)
*/
It seems that this join removal is also beyond the pg_hint_plan control ...
--
regards, Andrei Lepikhov
