From: Andreas Kretschmer <akretschmer@despammed.com>
To: pgsql-sql@postgresql.org
Cc: Andreas Kretschmer <akretschmer@despammed.com>
Subject: Re: [despammed] question about index
Date: Thu, 16 Dec 2004 15:15:57 +0100
Message-ID: <20041216141557.GA17096@Pinguin.wug-glas.de> (raw)
In-Reply-To: <20041216141025.GC2768@wolff.to>
References: <20041216104154.GA30578@mail.librelogiciel.com>
<20041216110139.GA5899@Pinguin.wug-glas.de>
<20041216141025.GC2768@wolff.to>
am 16.12.2004, um 8:10:25 -0600 mailte Bruno Wolff III folgendes:
> On Thu, Dec 16, 2004 at 12:01:39 +0100,
> Andreas Kretschmer <akretschmer@despammed.com> wrote:
> > >
> > > considering that almost 70% of the rows will be with 'VALUE1', 20%
> > > will be with 'VALUE2' and 10% will be with 'VALUE3' on the average.
> > >
> > > should I create an index to speedup the counts or not ?
> >
> > Yes.
>
> Indexes will probably not help in this case. Even when looking at 10% of
> the rows, a sequential scan is still going to be faster than an index
> scan in most cases.
Okay.
Andreas
--
Andreas Kretschmer (Kontakt: siehe Header)
Tel. NL Heynitz: 035242/47212
GnuPG-ID 0x3FFF606C http://wwwkeys.de.pgp.net
=== Schollglas Unternehmensgruppe ===
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-sql@postgresql.org
Cc: akretschmer@despammed.com
Subject: Re: [despammed] question about index
In-Reply-To: <20041216141557.GA17096@Pinguin.wug-glas.de>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox