Laurenz Albe <laurenz.albe@xxxxxxxxxxx> writes:Tom Lane wrote:
It doesn't happen for me either. Looking at the planner code, it seems
like the relkind check should happen first because it'd be cheaper than
the OR condition.
It is still unclear why the execution plan looks like that, but maybe
it would be more robust to change "has_sequence_privilege" so that it
just returns FALSE if the argument is not a sequence.
I was wondering about that, but somewhere along there we'd be losingall semblance of error checking on the OID argument, so it's not allthat attractive a solution. I'd prefer to understand why this isn'tbehaving the same as it does for other people before we resort to that.Axel, would you try two more things on that DB?explain select ((pg_has_role(relowner, 'USAGE'::text) OR has_sequence_privilege(oid, 'SELECT, UPDATE, USAGE'::text))) from pg_class;explain select (relkind = ’S'::"char") from pg_class;
nextcloud=> explain select ((pg_has_role(relowner, 'USAGE'::text) OR has_sequence_privilege(oid, 'SELECT, UPDATE, USAGE'::text))) from pg_class;
QUERY PLAN
-----------------------------------------------------------
Seq Scan on pg_class (cost=0.00..28.56 rows=656 width=1)
(1 row)
nextcloud=> explain select (relkind = 'S'::"char") from pg_class;
QUERY PLAN
-----------------------------------------------------------
Seq Scan on pg_class (cost=0.00..28.56 rows=656 width=1)
(1 row)
That's just to positively confirm that the planner thinks the former
_expression_ is more expensive than the latter.
Assuming that it does, the only other answer I can think of is that
there's something wrong with the insertion sort code in
order_qual_clauses. Pretty hard to see what, though.
