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Data Bases > Pgsql Performance > Forcing more ag...
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Forcing more agressive index scans for BITMAP AND

by Ow.Mun.Heng@[EMAIL PROTECTED] (Ow Mun Heng) Apr 7, 2008 at 04:15 PM

just wondering if there's a special tweak i can do to force more usage
of indexes to do BITMAP ands?

I have a table like

A int
B int
C int
D int
E int
F int
g int

where A/B/C/D/E are indexes

There's ~20millions rows in the table.

Query are something like this.

select * from table 
where A=X
and B = Y
and C = Z
and D = AA
and E = BB

the query plan will only pick 2 indexes to do the bitmap.
I'm not sure how to tweak the config for it to use more indexes.

Box is a celeron 1.7 w/ 768MB ram with shared buffers at 250MB and
effective cache size 350MB



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 4 Posts in Topic:
Forcing more agressive index scans for BITMAP AND
Ow.Mun.Heng@[EMAIL PROTEC  2008-04-07 16:15:51 
Re: Forcing more agressive index scans for BITMAP AND
matthew@[EMAIL PROTECTED]  2008-04-07 11:50:27 
Re: Forcing more agressive index scans for BITMAP AND
Ow.Mun.Heng@[EMAIL PROTEC  2008-04-08 13:42:51 
Re: Forcing more agressive index scans for BITMAP AND
matthew@[EMAIL PROTECTED]  2008-04-08 12:02:00 

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tan12V112 Mon Dec 1 7:23:58 CST 2008.