Re: Query optimization

On Fri, Sep 30, 2005 at 06:24:52PM -0400, Sean Davis wrote:
> -> Seq Scan on u_all_est_mrna c (cost=0.00..932582.74 rows=24225174
> width=179) (actual time=17.384..302484.904 rows=24225174 loops=1)

That step is where most of your time is being spent, which isn't
surprising given that it's scanning 24M rows. An index on
abs(tend-tstart) might help eliminate that. It will also probably help
if you increase the statistics_target for u_all_est_mrna, since it might
be best to join before filtering on abs(tend-tstart), which is the
opposite of what it's doing now.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby(at)pervasive(dot)com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461