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Re: Bitmap scans vs. the statistics views

From: Hannu Krosing <hannu(at)tm(dot)ee>
To: josh(at)agliodbs(dot)com
Cc: Jan Wieck <JanWieck(at)yahoo(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>,pgsql-hackers(at)postgresql(dot)org
Subject: Re: Bitmap scans vs. the statistics views
Date: 2005-04-22 23:40:50
Message-ID: 1114213250.6004.28.camel@fuji.krosing.net (view raw or flat)
Thread:
Lists: pgsql-hackers
On R, 2005-04-22 at 13:46 -0700, Josh Berkus wrote:
> Tom,
> 
> Hmmm ... we need to flag *something* in pg_stat_*_indexes, whether it is a new 
> column or the tuplefetch column.   People use that view to find indexes they 
> can drop.

I think that "idx_scan" and "idx_tup_read" can have the same meaning as
for other index types, i.e. of number of scans and number of index
tuples read (and copied into bitmap).

and as idx_tup_fetch seems to be == idx_tup_read, it can be the same for
bitmap indexes as well :)

but if the view will be changed, I'd like to see column idx_pages_read
added there.

-- 
Hannu Krosing <hannu(at)tm(dot)ee>

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