Re: Limit clause not using index

Yves Vindevogel wrote:

> rvponp=# explain analyze select * from tblPrintjobs order by
> loginuser, desceventdate, desceventtime ;
> QUERY PLAN
>
--------------------------------------------------------------------------------------------------------------------------------
>
> Sort (cost=345699.06..347256.49 rows=622972 width=203) (actual
> time=259438.952..268885.586 rows=622972 loops=1)
> Sort Key: loginuser, desceventdate, desceventtime
> -> Seq Scan on tblprintjobs (cost=0.00..25596.72 rows=622972
> width=203) (actual time=21.155..8713.810 rows=622972 loops=1)
> Total runtime: 271583.422 ms
> (4 rows)


Can you post it with the limit? I realize the query takes a long time,
but that is the more important query to look at.

Also, just as a test, if you can, try dropping most of the indexes
except for the important one. It might be that the planner is having a
hard time because there are too many permutations to try.
I believe if you drop the indexes inside a transaction, they will still
be there for other queries, and if you rollback instead of commit, you
won't lose anything.

BEGIN;
DROP INDEX ...
EXPLAIN ANALYZE SELECT *...
ROLLBACK;

John
=:->