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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Kevin Grittner <Kevin.Grittner@wicourts.gov>
Cc: pgsql-performance@postgresql.org
Subject: Re: Planner reluctant to start from subquery
Date: Wed, 01 Feb 2006 15:53:08 -0500
Message-ID: <4611.1138827188@sss.pgh.pa.us> (raw)
In-Reply-To: <43E0C8F5.EE98.0025.0@wicourts.gov>
References: <43E0AA7E.EE98.0025.0@wicourts.gov>
	<43E0AA7E.EE98.0025.0@wicourts.gov>
	<3759.1138822464@sss.pgh.pa.us>
	<43E0BEDD.EE98.0025.0@wicourts.gov>
	<43E0BEDD.EE98.0025.0@wicourts.gov>
	<4218.1138824885@sss.pgh.pa.us>
	<43E0C4A7.EE98.0025.0@wicourts.gov>
	<43E0C4A7.EE98.0025.0@wicourts.gov>
	<4359.1138826175@sss.pgh.pa.us>
	<43E0C8F5.EE98.0025.0@wicourts.gov>

"Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
> Since you were so confident it couldn't be the outer join, I went
> looking for what else I changed at the same time.  I eliminated the code
> referencing that table, which contained an OR.  I've seen ORs cause
> nasty problems with optimizers in the past.  I took out the OR in the
> where clause, without eliminating that last outer join, and it optimized
> fine.

I don't think that OR is relevant either, since again it's present in
both the well-optimized and badly-optimized variants that you posted.

			regards, tom lane



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