Skip site navigation (1) Skip section navigation (2)

Re: 1-/2-dimensional indexes for common columns, rationale?

From: "A(dot) Kretschmer" <andreas(dot)kretschmer(at)schollglas(dot)com>
To: pgsql-performance(at)postgresql(dot)org
Subject: Re: 1-/2-dimensional indexes for common columns, rationale?
Date: 2008-03-26 15:02:08
Message-ID: 20080326150208.GH27264@a-kretschmer.de (view raw or flat)
Thread:
Lists: pgsql-performance
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

In response to

Responses

pgsql-performance by date

Next:From: Marinos YannikosDate: 2008-03-26 15:15:20
Subject: Re: 1-/2-dimensional indexes for common columns, rationale?
Previous:From: Marinos YannikosDate: 2008-03-26 14:18:53
Subject: 1-/2-dimensional indexes for common columns, rationale?

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group