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Re: Wrong plan sequential scan instead of an index one

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Richard Huxton <dev(at)archonet(dot)com>
Cc: Gaetano Mendola <gmendola(at)mbigroup(dot)it>, "pgsql-performance(at)postgresql(dot)org" <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Wrong plan sequential scan instead of an index one
Date: 2007-03-30 16:13:00
Message-ID: 20399.1175271180@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-performance
Richard Huxton <dev(at)archonet(dot)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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