Re: bitmapscan test, no success, again - Mailing list pgsql-hackers

From Pavel Stehule
Subject Re: bitmapscan test, no success, again
Date
Msg-id Pine.LNX.4.44.0504261342260.1977-100000@kix.fsv.cvut.cz
Whole thread Raw
In response to bitmapscan test, no success, bs is not faster  (Pavel Stehule <stehule@kix.fsv.cvut.cz>)
List pgsql-hackers
Hello,

I get success, with my hyphotetic sample on big table (100000 rec) Bitmap 
index scan is really usefull.

I tested select count(*) from foo where  v IN (11,11,23,11,11,11,11,11,22,71,11)

Some notes.

1. with bitmap index scan 7.16 ms 
2. without bis 165.731 ms (seq. scan) !!!!

3. list of constant contains equals values. Is possible remove it? explain analyze select count(*) from foo   where v
in(11,11,11,12)
 

Regards

Pavel Stehule 






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