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Date: Tue, 21 Nov 2006 16:12:47 +0100 (CET)
Subject: Re: BitMapScan performance degradation
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Cc: "PostgreSQL Performance" <pgsql-performance@postgresql.org>,
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> When enable_bitmapscan is enabled this query cost 51893.491 ms and when
> is disabled 117.709 ms. But i heard bitmapscan feature improved
> performance, can you help me ?

The standard question we always ask first is if you have run VACUUM
ANALYZE recently?

Are all the costs and estimated number of rows the same after you have run
VACUUM ANALYZE? If not you might want to show that new plan as well.

/Dennis