From: Robert Klemme <shortcutter@googlemail.com>
To: pgsql-performance@postgresql.org
Subject: Re: bitmask index
Date: Thu, 23 Jun 2011 17:55:35 +0200
Message-ID: <itvnln$vcd$1@dough.gmane.org> (raw)
In-Reply-To: <4E0261C1.8000807@2ndQuadrant.com>
References: <4E025E54.6020402@engene.se>
<4E0261C1.8000807@2ndQuadrant.com>
On 06/22/2011 11:42 PM, Greg Smith wrote:
> On 06/22/2011 05:27 PM, Marcus Engene wrote:
>> I have some tables with bitmask integers. Set bits are the interesting
>> ones. Usually they are sparse.
>
> If it's sparse, create a partial index that just includes rows where the
> bit is set:
> http://www.postgresql.org/docs/current/static/indexes-partial.html
That would mean that if different bits are queried there would need to
be several of those indexes.
Maybe it's an alternative to index all rows where misc_bits <> 0 and
include that criterion in the query.
Kind regards
robert
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To: pgsql-performance@postgresql.org
Cc: shortcutter@googlemail.com
Subject: Re: bitmask index
In-Reply-To: <itvnln$vcd$1@dough.gmane.org>
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