From: Marinos Yannikos <mjy@geizhals.at>
To: pgsql-performance@postgresql.org
Subject: Re: 1-/2-dimensional indexes for common columns, rationale?
Date: Wed, 26 Mar 2008 16:15:20 +0100
Message-ID: <47EA6888.2050506@geizhals.at> (raw)
In-Reply-To: <20080326150208.GH27264@a-kretschmer.de>
References: <47EA5B4D.5000300@geizhals.at>
<20080326150208.GH27264@a-kretschmer.de>
A. Kretschmer schrieb:
>> create index foo1 on bla (a);
>> create index foo2 on bla (b);
>> create index foo3 on bla (a,b);
>>[...]
>
> 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)
8.3.1 - foo3 is being used though in presence of both foo1 and foo2, so
I'd suppose that it's a better choice even with bitmap index scan
available...
-mjy
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To: pgsql-performance@postgresql.org
Cc: mjy@geizhals.at
Subject: Re: 1-/2-dimensional indexes for common columns, rationale?
In-Reply-To: <47EA6888.2050506@geizhals.at>
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