To: pgsql-sql@postgresql.org
From: Wiebe Cazemier <halfgaar@gmx.net>
Subject: Re: Joins on many-to-many relations.
Date: Thu, 15 Mar 2007 15:16:07 +0100
Lines: 11
Message-ID: <etbkf8$2me$1@sea.gmane.org>
References: <et94vu$qdt$1@sea.gmane.org>
	<5.2.1.1.0.20070314133826.050002b0@pop6.sympatico.ca>
	<et9r79$kj5$1@sea.gmane.org>
	<a55915760703150705j3b4c2b3esd94d4a27d31ee658@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8Bit
User-Agent: KNode/0.10.4

On Thursday 15 March 2007 15:05, Rodrigo De León wrote:

> From http://www.postgresql.org/docs/8.2/static/indexes-types.html :
> 
> "The optimizer can also use a B-tree index for queries involving the
> pattern matching operators LIKE and ~ if the pattern is a constant and
> is anchored to the beginning of the string ? for example, col LIKE
> 'foo%' or col ~ '^foo', but not col LIKE '%bar'."

It made the query faster (1500 instead of 2500 ms), but not fast enough. But,
this is good to know, although I often need the '%foobar%' search string...