Re: Slow Query- Bad Row Estimate

I had just analyzed the dealergroupgeochache table. Wow. Thank you. That did the trick. Can you give me an explanation of the default_stats work? I don't think I completely understand what it means when you set it to 500 instead of 1000?

thanks
-----Original Message-----
From: pgsql-performance-owner(at)postgresql(dot)org [mailto:pgsql-performance-owner(at)postgresql(dot)org] On Behalf Of Josh Berkus
Sent: Friday, October 29, 2010 2:10 PM
To: pgsql-performance(at)postgresql(dot)org
Subject: Re: [PERFORM] Slow Query- Bad Row Estimate

On 10/29/10 1:54 PM, Ozer, Pam wrote:
> " -> Index Scan using dealergroupgeocache_i01 on
> dealergroupgeocache (cost=0.00..5719.56 rows=9055 width=10) (actual
> time=0.015..87.689 rows=163491 loops=1)"

This appears to be your problem here.

a) when was dealergroupgeocache last ANALYZED?

b) try increasing the stats_target on dealergroupid and regionid, to say
500 and re-analyzing.

--
-- Josh Berkus
PostgreSQL Experts Inc.
http://www.pgexperts.com

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