Right now, I am having trouble getting the planner to optimize queries
in the form of
select t.key, t.field from t a
where
(
select count(*) from t b
where b.field a.field
) = k
The subplan (either index or seq. scan) executes once for each row in t,
which of
Merlin,
select t.key, t.field from t a
where
(
select count(*) from t b
where b.field a.field
) = k
The subplan (either index or seq. scan) executes once for each row in t,
which of course takes forever.
This query is a way of achieving LIMIT type results
Title: RE: [PERFORM] is it possible to for the planner to optimize this form?
I didn't really look that closely at the problem but have you thought of trying:
select t.key, t.field from t a
, (select count(*) as cntb from t b
where b.field a.field) as dmytbl
where
cntb = k
This is
