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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