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From: Josh Berkus <josh@agliodbs.com>
Reply-To: josh@agliodbs.com
Organization: Aglio Database Solutions
To: pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] bitmap scan issues 8.1 devel
Date: Wed, 17 Aug 2005 14:33:15 -0700
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Cc: "Merlin Moncure" <merlin.moncure@rcsonline.com>,
	pgsql-performance@postgresql.org
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Merlin,

> =A0 =A0-> =A0Index Scan using product_structure_file_pkey on
> product_structure_file =A0(cost=3D0.00..45805.23 rows=3D5722 width=3D288)
> (actual time=3D0.063..0.063 row
> s=3D1 loops=3D1)

It appears that your DB is estimating the number of rows returned much too=
=20
high (5722 instead of 1).  Please raise the statistics on all columns to=20
about 500, analyze, and try your test again.

Thanks!

=2D-=20
=2D-Josh

Josh Berkus
Aglio Database Solutions
San Francisco