Re: Increasing select max(datecol) from bilkaib wheredatecol<=date'2008-11-01' and (cr='00' or db='00') speed

From: "Andrus" <kobruleht2(at)hot(dot)ee>
To: pgsql-performance(at)postgresql(dot)org
Subject: Re: Increasing select max(datecol) from bilkaib wheredatecol<=date'2008-11-01' and (cr='00' or db='00') speed
Date: 2008-11-12 19:57:06
Message-ID: gffcgj$1sjh$1@news.hub.org
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Depesz,

> do you always have this: "(cr='00' or db='00')"? or do the values (00)
> change?
> if they don't change, or *most* of the queries have "(cr='00' or
> db='00')", than the biggest time difference you will get after creating
> this index:
> create index test on bilkaib (kuupaev) where cr='00' or db='00';

I have always cr='00' or db='00' clause. Separate values are never tested.
I changed by queries back to old values and created this single index.
This seems to be even better that Vladimir suggestion.
Thank you very much.

Andrus.

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