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Re: Questions on query planner, join types, and work_mem

From: Jayadevan M <Jayadevan(dot)Maymala(at)ibsplc(dot)com>
To: Peter Hussey <peter(at)labkey(dot)com>
Cc: pgsql-performance <pgsql-performance(at)postgresql(dot)org>,pgsql-performance-owner(at)postgresql(dot)org
Subject: Re: Questions on query planner, join types, and work_mem
Date: 2010-07-28 04:27:29
Message-ID: OF7B3491A5.E3985E12-ON6525776E.00184195-6525776E.00189A25@ibsplc.com (view raw or flat)
Thread:
Lists: pgsql-performance
Hello,
> the join column, lsid, is a poor choice for a join column as it is a
> long varchar value (avg length 101 characters) that us only gets 
> unique way out on the right hand side.
Would a join on subtring on the 'way out on the right hand side' (did you 
mean 'rightmost characters' or 'only when we take almost all the 101 
characters'?) together with a function based index help?
Regards,
Jayadevan





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