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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Rural Hunter <ruralhunter@gmail.com>
cc: pgsql-performance@postgresql.org
Subject: Re: how to change the index chosen in plan?
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Comments: In-reply-to Rural Hunter <ruralhunter@gmail.com>
	message dated "Fri, 08 Jun 2012 21:33:08 +0800"
Date: Fri, 08 Jun 2012 10:10:58 -0400
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Rural Hunter <ruralhunter@gmail.com> writes:
> I have a query like this:
> select a.* from a inner join b on a.aid=b.aid where a.col1=33 a.col2=44 
> and b.bid=8
> postgresql selected the index on a.col1 then selected the index on 
> b.bid. But in my situation, I know that the query will be faster if it 
> chose the index on b.bid first since there are only a few rows with 
> value 8.

If you know that and the planner doesn't, maybe ANALYZE is called for.

			regards, tom lane