From: Tom Lane <tgl@sss.pgh.pa.us>
To: Richard Huxton <dev@archonet.com>
Cc: Gaetano Mendola <gmendola@mbigroup.it>
Cc: pgsql-performance@postgresql.org <pgsql-performance@postgresql.org>
Subject: Re: Wrong plan sequential scan instead of an index one
Date: Fri, 30 Mar 2007 12:13:00 -0400
Message-ID: <20399.1175271180@sss.pgh.pa.us> (raw)
In-Reply-To: <460CF902.4020707@archonet.com>
References: <460CD941.6080303@bigfoot.com>
<460CDCDC.7020901@archonet.com>
<460CE359.8060208@bigfoot.com>
<460CE775.8080908@archonet.com>
<460CF40F.6060303@mbigroup.it>
<460CF902.4020707@archonet.com>
Richard Huxton <dev@archonet.com> writes:
> Ah, but it's got no way of knowing what matches you'll get for
> '%anything%'. There's no easy way to get statistics for matching substrings.
8.2 actually tries the match on the most-common-values list, if said
list is big enough (I think the threshold is stats target = 100).
Not sure if that will help here, though.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, dev@archonet.com, gmendola@mbigroup.it
Subject: Re: Wrong plan sequential scan instead of an index one
In-Reply-To: <20399.1175271180@sss.pgh.pa.us>
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