Re: [HACKERS] ORDER BY optimisations

From: jwieck(at)debis(dot)com (Jan Wieck)
To: jwieck(at)debis(dot)com
Cc: hannu(at)trust(dot)ee, hackers(at)postgreSQL(dot)org
Subject: Re: [HACKERS] ORDER BY optimisations
Date: 1998-10-31 17:07:04
Message-ID: m0zZeUT-000EBPC@orion.SAPserv.Hamburg.dsh.de
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> 1. the plan is a Sort->IndexScan,
>
> 2. there is an ORDER BY clause,
>
> 3. the index choosen by the planner matches ALL attributes
> given in the ORDER BY clause (extra indexed attributes
> not in ORDER BY ignored),

Ooops - sorry. Took another look at the patch and saw, that
it actually does not ignore extra attributes in the index.
Maybe you want to force sort suppression then too and comment
out the 'return TRUE' for this case.

BTW: This or an enhanced version (suppressing more stupid
sort cases) is my first candidate for the v6.4.1 feature
patch.

Jan

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#======================================== jwieck(at)debis(dot)com (Jan Wieck) #

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