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From: Dave Cramer <pg@fastcrypt.com>
To: sathiya psql <sathiya.psql@gmail.com>
Cc: A. Kretschmer <andreas.kretschmer@schollglas.com>
Cc: Mark Mielke <mark@mark.mielke.cc>
Cc: pgsql-performance@postgresql.org
Subject: Re: count * performance issue
Date: Thu, 6 Mar 2008 06:50:17 -0500
Message-ID: <B94D3180-BB72-43EB-BA1E-90CF53705386@fastcrypt.com> (raw)
In-Reply-To: <f966c2ee0803052243w723e2866gbfc37128620d1c6d@mail.gmail.com>
References: <f966c2ee0803052142l6a105678jfe2da92a0d9371@mail.gmail.com>
	<f966c2ee0803052143k4570d771o6c300647d3b987d@mail.gmail.com>
	<20080306060829.GA21084@a-kretschmer.de>
	<bf54be870803052215y5bb56235k5ea05ada1d701022@mail.gmail.com>
	<47CF8EA6.8070503@mark.mielke.cc>
	<20080306063643.GB21084@a-kretschmer.de>
	<f966c2ee0803052243w723e2866gbfc37128620d1c6d@mail.gmail.com>


On 6-Mar-08, at 1:43 AM, sathiya psql wrote:

> is there any way to explicitly force the postgres to use index scan
>
>

If you want to count all the rows in the table there is only one way  
to do it (without keeping track yourself with a trigger ); a seq scan.

An index will not help you.

The only thing that is going to help you is really fast disks, and  
more memory, and you should consider moving to 8.3 for all the other  
performance benefits.

Dave 

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