From: John A Meinel <john@arbash-meinel.com>
To: lutzeb@aeccom.com
Cc: Greg Stark <gsstark@mit.edu>
Cc: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us
Subject: Re: query produces 1 GB temp file
Date: Sun, 06 Feb 2005 09:19:08 -0600
Message-ID: <4206356C.9060308@arbash-meinel.com> (raw)
In-Reply-To: <42061B35.6000306@aeccom.com>
References: <20050205182117.0125074@mail2.aeccom.com>
<87y8e2kb8j.fsf@stark.xeocode.com>
<42061B35.6000306@aeccom.com>
Dirk Lutzebaeck wrote:
> Greg,
>
> Thanks for your analysis. But I dont get any better after bumping
> STATISTICS target from 10 to 200.
> explain analyze shows that the optimizer is still way off estimating
> the rows. Is this normal? It still produces a 1 GB temp file.
> I simplified the query a bit, now only two tables are involved (bi,
> df). I also vacuumed.
Are you just doing VACUUM? Or are you doing VACUUM ANALYZE? You might
also try VACUUM ANALYZE FULL (in the case that you have too many dead
tuples in the table).
VACUUM cleans up, but doesn't adjust any planner statistics without ANALYZE.
John
=:->
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To: pgsql-performance@postgresql.org
Cc: john@arbash-meinel.com, lutzeb@aeccom.com, gsstark@mit.edu, tgl@sss.pgh.pa.us
Subject: Re: query produces 1 GB temp file
In-Reply-To: <4206356C.9060308@arbash-meinel.com>
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