From: Tom Lane <tgl@sss.pgh.pa.us>
To: Craig James <craig_james@emolecules.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Auto-ANALYZE?
Date: Wed, 23 May 2007 19:55:58 -0400
Message-ID: <26268.1179964558@sss.pgh.pa.us> (raw)
In-Reply-To: <4654D26E.1020208@emolecules.com>
References: <4654D26E.1020208@emolecules.com>
Craig James <craig_james@emolecules.com> writes:
> Auto-vacuum has made Postgres a much more "friendly" system. Is there some reason the planner can't also auto-ANALYZE in some situations?
autovacuum handles analyze too. Trying to make the planner do it is
a crummy idea for a couple of reasons:
* unpredictable performance if queries sometimes go off for a few
seconds to collect stats
* pg_statistics update requires semi-exclusive lock
* work is lost if transaction later rolls back
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, craig_james@emolecules.com
Subject: Re: Auto-ANALYZE?
In-Reply-To: <26268.1179964558@sss.pgh.pa.us>
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