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Message-ID: <adf34c300706230615j4763748dn9e1dae2cb5c2524c@mail.gmail.com>
Date: Sat, 23 Jun 2007 15:15:22 +0200
From: "Stefan Arentz" <stefan.arentz@gmail.com>
To: "Andreas Kretschmer" <akretschmer@spamfence.net>
Subject: Re: Counting all rows
Cc: pgsql-sql@postgresql.org
In-Reply-To: <20070623103856.GE7307@KanotixBox>
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References: <adf34c300706230315y43ba92daqf0804b7c377ffd29@mail.gmail.com>
	<20070623103856.GE7307@KanotixBox>

On 6/23/07, Andreas Kretschmer <akretschmer@spamfence.net> wrote:
> Stefan Arentz <stefan.arentz@gmail.com> schrieb:
>
> > I need to get statistics from a bunch of tables. Simply the number of
> > records in them.
> >
> > The query plan looks like this:
> >
> > => explain select count(id) from stuff;
> >                             QUERY PLAN
> > -------------------------------------------------------------------
> >  Aggregate  (cost=1629.69..1629.70 rows=1 width=8)
> >    ->  Seq Scan on stuff  (cost=0.00..1517.75 rows=44775 width=8)
> >
> > The sequential scan kind of worries me. Is there a better/faster way to do
> > this?
>
> Yes.
>
> A "select count(*) from foo;" enforces a seq. scan. Solutions for this
> are discussed here: http://www.varlena.com/GeneralBits/120.php

Thank you Andreas. That is exactly what I was looking for.

 S.