From: | Martijn van Oosterhout <kleptog(at)svana(dot)org> |
---|---|
To: | Jonas Henriksen <jonas(dot)f(dot)henriksen(at)gmail(dot)com> |
Cc: | pgsql-general(at)postgresql(dot)org |
Subject: | Re: strange query filter problems |
Date: | 2006-04-19 12:08:09 |
Message-ID: | 20060419120809.GI15420@svana.org |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
On Wed, Apr 19, 2006 at 01:53:46PM +0200, Jonas Henriksen wrote:
> Yes, explain analyze looks like this:
Well, incorrect statistics are definitly the culprit, look:
> " -> Index Scan using sskjema_pkey on sskjema s (cost=0.00..3868.95 rows=9738 width=157) (actual time=104.465..208.185 rows=14417 loops=1)"
50% off, not bad.
> " -> Index Scan using speciesix on tskjema t (cost=0.00..6.01 rows=1 width=75) (actual time=0.140..24.594 rows=1703 loops=1)"
> " Index Cond: ((species ~>=~ 'TAGGMAKRELL'::bpchar) AND (species ~<~ 'TAGGMAKRELM'::bpchar))"
> " Filter: (species ~~ 'TAGGMAKRELL%'::text)"
Youch, 170200% percent off, which explains why it gets wildly bad
timings. Can you increase the statistics on the species column? Check
the docs for how.
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> From each according to his ability. To each according to his ability to litigate.
From | Date | Subject | |
---|---|---|---|
Next Message | dsids | 2006-04-19 12:25:15 | tomcat postgresql database connectivity error |
Previous Message | Jonas Henriksen | 2006-04-19 11:53:46 | Re: strange query filter problems |