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To: "Guillaume Smet" <guillaume.smet@gmail.com>
cc: pgsql-performance <pgsql-performance@postgresql.org>
Subject: Re: Estimation problem with a LIKE clause containing a / 
In-reply-to: <17767.1194453292@sss.pgh.pa.us> 
References: <1d4e0c10711070453q214f089cpd144cbb5193d3c4f@mail.gmail.com>
	<17767.1194453292@sss.pgh.pa.us>
Comments: In-reply-to Tom Lane <tgl@sss.pgh.pa.us>
	message dated "Wed, 07 Nov 2007 11:34:52 -0500"
Date: Wed, 07 Nov 2007 18:14:08 -0500
Message-ID: <11467.1194477248@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
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I wrote:
> "Guillaume Smet" <guillaume.smet@gmail.com> writes:
>> [ bad estimate for LIKE ]

> Hmmm ... what locale are you working in?  I notice that the range
> estimator for this pattern would be "ancestors >= '1062/' AND
> ancestors < '10620'", which will do the right thing in C locale
> but maybe not so much elsewhere.

I've applied a patch that might help you:
http://archives.postgresql.org/pgsql-committers/2007-11/msg00104.php

			regards, tom lane