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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Craig A. James <cjames@modgraph-usa.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Poor performance o
Date: Tue, 21 Mar 2006 18:33:15 -0500
Message-ID: <6629.1142983995@sss.pgh.pa.us> (raw)
In-Reply-To: <442080D1.5090803@modgraph-usa.com>
References: <43F38867.6010701@gpdnet.co.uk>
	<19510.1140036968@sss.pgh.pa.us>
	<19779.1140038874@sss.pgh.pa.us>
	<43F39E53.1020009@gpdnet.co.uk>
	<20781.1140046109@sss.pgh.pa.us>
	<19570.1142971720@sss.pgh.pa.us>
	<442080D1.5090803@modgraph-usa.com>

"Craig A. James" <cjames@modgraph-usa.com> writes:
> It looks to me like the problem is the use of nested loops when a hash join should be used, but I'm no expert at query planning.

Given the sizes of the tables involved, you'd likely have to boost up
work_mem before the planner would consider a hash join.  What nondefault
configuration settings do you have, anyway?

			regards, tom lane

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