From: A. Kretschmer <andreas.kretschmer@schollglas.com>
To: pgsql-performance@postgresql.org
Subject: Re: 1-/2-dimensional indexes for common columns, rationale?
Date: Wed, 26 Mar 2008 16:02:08 +0100
Message-ID: <20080326150208.GH27264@a-kretschmer.de> (raw)
In-Reply-To: <47EA5B4D.5000300@geizhals.at>
References: <47EA5B4D.5000300@geizhals.at>
am Wed, dem 26.03.2008, um 15:18:53 +0100 mailte Marinos Yannikos folgendes:
> Hello,
>
> we have several indexes such as:
>
> create index foo1 on bla (a);
> create index foo2 on bla (b);
> create index foo3 on bla (a,b);
>
> They are all used often by frequently used queries (according to
> pg_statio_user_indexes), but we need somewhat higher INSERT/UPDATE
> performance (having tuned most other things) so we'd like to remove some.
Which version do you have? Since 8.1 pg can use a so called 'bitmap
index scan', because of this feature i guess you don't need the index
foo3. (if you have 8.1 or higher)
Andreas
--
Andreas Kretschmer
Kontakt: Heynitz: 035242/47150, D1: 0160/7141639 (mehr: -> Header)
GnuPG-ID: 0x3FFF606C, privat 0x7F4584DA http://wwwkeys.de.pgp.net
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-performance@postgresql.org
Cc: andreas.kretschmer@schollglas.com
Subject: Re: 1-/2-dimensional indexes for common columns, rationale?
In-Reply-To: <20080326150208.GH27264@a-kretschmer.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