Bitmap Scan Pages

From: Listmail <lists(at)peufeu(dot)com>
To: "pgsql-general(at)postgresql(dot)org" <pgsql-general(at)postgresql(dot)org>
Subject: Bitmap Scan Pages
Date: 2007-04-25 06:36:45
Message-ID: op.trbtzjlwzcizji@apollo13
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Hello,

Is there a way to know how many pages were hit by a Bitmap Heap scan ?

For instance :

Bitmap Heap Scan on posts
(cost=56.71..295.24 rows=2123 width=67)
(actual time=0.575..1.462 rows=2160 loops=1)

I'd like to know if it hit 2160 pages (ie I should really run CLUSTER) or
50 pages (ie. my table is well clustered, everything cool).
Since, when it's cached, it's so fast anyway I cant' tell the difference,
but when it's not cached, it is important.

This would give an interesting probe for EXPLAIN ANALYZE tuning...

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