Date: Wed, 14 Jul 2010 15:44:10 +0200
From: Reinoud van Leeuwen <reinoud.v@n.leeuwen.net>
To: pgsql-sql@postgresql.org
Subject: Re: Question on COUNT performance
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On Wed, Jul 14, 2010 at 07:30:39AM -0600, Joshua Tolley wrote:

> > Have you tried 'select count (1)..."?
> 
> If this helps at all, it's unlikely to help much. I remember having seen
> discussion somewhere that there's an optimization such that count(*) and
> count(1) do the same thing anyway, but I can't find it in the code
> immediately. 

oops, I was thinking too much about Sybase (where is makes a huge 
difference, since the optimiser sees that everything it needs can be found 
in the index so the table does not have to be read at all).

Reinoud

-- 
__________________________________________________
"Nothing is as subjective as reality"
Reinoud van Leeuwen    reinoud.v@n.leeuwen.net
http://reinoud.van.leeuwen.net kvk 27320762
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