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From: Andrew Lazarus <andrew@pillette.com>
To: Yves Vindevogel <yves.vindevogel@implements.be>
Cc: pgsql-performance@postgresql.org
Subject: Re: Fwd: Index on table when using DESC clause
Date: Mon, 23 May 2005 13:27:15 -0700
Message-ID: <42923CA3.1040306@pillette.com> (raw)
In-Reply-To: <6d31bed04ab35cbbe2df37af979d9882@implements.be>
References: <6d31bed04ab35cbbe2df37af979d9882@implements.be>

As far as I know, to use a straight index Postgres requires either

ORDER BY pages, description -- or --
ORDER BY pages DESC, description DESC.

If you want the results by pages DESC, description ASC, then you have to 
make an index on an expression or define your own operator or something 
esoteric like that. I would think the ability to have an index where the 
columns don't all collate in the same direction would be an easy feature 
to add.

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