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To: "Josh Berkus" <josh@agliodbs.com>, "Tobias Brox" <tobixen@gmail.com>
Cc: pgsql-performance@postgresql.org, "Mladen Gogala"
	<mladen.gogala@vmsinfo.com>
Subject: Re: Why we don't want hints Was: Slow count(*) again...
References: <201102012247.p11Ml6u02682@momjian.us>
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	<4D4AD9F6.6040903@vmsinfo.com> <4D4AE16E.9040807@peak6.com>
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Date: Fri, 11 Feb 2011 15:51:44 +0100
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From: "Pierre C" <lists@peufeu.com>
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>    select * from account_transaction where trans_type_id in ( ...
> long, hard-coded list ...) and account_id=? order by created desc
> limit 25;

You could use an index on (account_id, created, trans_type), in  
replacement of your index on (account_id, created). This will not prevent  
the "Index Scan Backwards", but at least, index rows with trans_type not  
matching the WHERE clause will not generate any heap access...