Re: BUG #3225: BitmapOr plan node does not show currect row count - Mailing list pgsql-bugs

From Tom Lane
Subject Re: BUG #3225: BitmapOr plan node does not show currect row count
Date
Msg-id 19389.1176477250@sss.pgh.pa.us
Whole thread Raw
In response to BUG #3225: BitmapOr plan node does not show currect row count  ("Jens-Wolfhard Schicke" <j.schicke@asco.de>)
Responses Re: BUG #3225: BitmapOr plan node does not show currect row count
List pgsql-bugs
"Jens-Wolfhard Schicke" <j.schicke@asco.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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