From: Elias Ghanem <e.ghanem@acteos.com>
To: pgsql-performance@postgresql.org
Subject: Queries with conditions using bitand operator
Date: Tue, 13 Jul 2010 14:48:09 +0300
Message-ID: <4C3C5279.5090108@acteos.com> (raw)
Hi,
I have table "ARTICLE" containing a String a field "STATUS" that
represents a number in binary format (for ex: 10011101).
My application issues queries with where conditions that uses BITAND
operator on this field (for ex: select * from article where status & 4 = 4).
Thus i'm facing performance problemes with these select queries: the
queries are too slow.
Since i'm using the BITAND operator in my conditions, creating an index
on the status filed is useless
and since the second operator variable (status & 4 = 4; status & 8 =
8; status & 16 = 16...) a functional index is also usless (because a
functional index require the use of a function that accept only table
column as input parameter: constants are not accepted).
So is there a way to enhance the performance of these queries?
Thanks,
Elias
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Cc: e.ghanem@acteos.com
Subject: Re: Queries with conditions using bitand operator
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