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Re: left join on a view takes significantly more time.

From: Josh Berkus <josh(at)agliodbs(dot)com>
To: Manuel Sugawara <masm(at)fciencias(dot)unam(dot)mx>,pgsql-sql(at)postgresql(dot)org
Subject: Re: left join on a view takes significantly more time.
Date: 2004-03-31 23:49:29
Message-ID: 200403311549.29211.josh@agliodbs.com (view raw or flat)
Thread:
Lists: pgsql-sql
Manuel,

> I'm facing a wired problem. When I left join two tables PostgreSQL is
> able to do it fast using the corresponding indices, However, if I
> define a simple view (to format the data) on one of the tables, the
> left join does not use the indices. Is something wrong here?

At a guess, the complex CASE statements are causing the planner to behave 
badly.   What happens if you do a straight join and not a left join?

Also, it's generally a good idea to put your join expression in the same order 
as the referenced tables.  You confused me and you could confuse the planner 
at some stage.

-- 
-Josh Berkus
 Aglio Database Solutions
 San Francisco


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