Kenneth Marshall wrote:
On Thu, Jun 10, 2010 at 12:34:07PM -0700, Anne Rosset wrote:
Jochen Erwied wrote:
Thursday, June 10, 2010, 8:36:08 PM you wrote:
psrdb=# (SELECT
psrdb(# MAX(item_rank.rank) AS maxRank
psrdb(# FROM
psrdb(# item_rank item_rank
psrdb(# WHERE
psrdb(# item_rank.project_id='proj2783'
psrdb(# AND item_rank.pf_id IS NULL
psrdb(#
psrdb(# )
psrdb-# ORDER BY
psrdb-# maxRank DESC;
Don't think it does really matter, but why do you sort a resultset
consisting of only one row?
Sorry, I should have removed the ORDER by (the full query has a union).
So without the ORDER by, here are the results:
psrdb=# SELECT
psrdb-# MAX(item_rank.rank) AS maxRank
psrdb-# FROM
psrdb-# item_rank item_rank
psrdb-# WHERE
psrdb-# item_rank.pf_id='plan1408';
maxrank
-------------
20504000000
(1 row)
Time: 1.516 ms
psrdb=# SELECT
psrdb-# MAX(item_rank.rank) AS maxRank
psrdb-# FROM
psrdb-# item_rank item_rank
psrdb-# WHERE
psrdb-# item_rank.project_id='proj2783'
psrdb-# AND item_rank.pf_id IS NULL;
maxrank
-------------
20200000000
(1 row)
Time: 13.177 ms
Is there anything that can be done for the second one?
Thanks,
Anne
What about an IS NULL index on pf_id?
Regards,
Ken
Hi Ken,
I have the following index:
"item_rank_index2" btree (project_id) WHERE (pf_id IS NULL)
Are you suggesting something else?
Thanks,
Anne
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