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Re: BUG #3225: BitmapOr plan node does not show currect row count

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Jens-Wolfhard Schicke" <j(dot)schicke(at)asco(dot)de>
Cc: pgsql-bugs(at)postgresql(dot)org
Subject: Re: BUG #3225: BitmapOr plan node does not show currect row count
Date: 2007-04-13 15:14:10
Message-ID: 19389.1176477250@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-bugs
"Jens-Wolfhard Schicke" <j(dot)schicke(at)asco(dot)de> writes:
> I an explain analyze I saw recently, a BitmapOr node of 5 Bitmap Index Scan
> looked like this:
> BitmapOr  (cost=43.57..43.57 rows=1833 width=0) (actual time=0.146..0.146
> rows=0 loops=1)

BitmapOr and BitmapAnd don't attempt to count their result rows --- doing
so would involve an extra scan over the bitmap, and what would you do
for lossy pages?

			regards, tom lane

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Next:From: Tom LaneDate: 2007-04-13 15:15:45
Subject: Re: BUG #3224: Dump: missing schema name for sequence in a "DEFAULT nextval" specification
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Subject: BUG #3227: ODBC driver with subqueries destroy transaction context

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