On Apr 25, 2007, at 7:36 AM, Listmail wrote:
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...

If you don't have anything else running in the database and you've got stats_block_level on, you could probably determine how many pages are being run by consulting the appropriate pg_statio_* view.
--
Jim Nasby                                            [EMAIL PROTECTED]
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)



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