From: Simon Riggs <simon@2ndquadrant.com>
To: Kevin Grittner <Kevin.Grittner@wicourts.gov>
Cc: pgsql-performance@postgresql.org
Subject: Re: hashjoin chosen over 1000x faster plan
Date: Wed, 10 Oct 2007 07:31:44 +0100
Message-ID: <1191997904.4233.125.camel@ebony.site> (raw)
In-Reply-To: <470B99BE.EE98.0025.0@wicourts.gov>
References: <470B99BE.EE98.0025.0@wicourts.gov>
On Tue, 2007-10-09 at 15:09 -0500, Kevin Grittner wrote:
> I have a situation where a query is running much slower than I would
> expect. The ANALYZE showed that it is hashing some information which
> is rarely needed. When I set enable_hashjoin = off for the
> connection the query run in 1/1000 the time.
Can you confirm the two queries give identical outputs? It isn't clear
to me why the second sort is (never executed) in your second plan, which
I would only expect to see for an inner merge join.
Can you show the details for ControlRecord also.
--
Simon Riggs
2ndQuadrant http://www.2ndQuadrant.com
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To: pgsql-performance@postgresql.org
Cc: simon@2ndquadrant.com, Kevin.Grittner@wicourts.gov
Subject: Re: hashjoin chosen over 1000x faster plan
In-Reply-To: <1191997904.4233.125.camel@ebony.site>
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