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Re: Posible planner improvement?

From: Richard Huxton <dev(at)archonet(dot)com>
To: Albert Cervera Areny <albert(at)sedifa(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Posible planner improvement?
Date: 2008-05-21 10:48:05
Message-ID: 4833FDE5.8090603@archonet.com (view raw or flat)
Thread:
Lists: pgsql-performance
Albert Cervera Areny wrote:
> I've got a query similar to this:
> 
> select * from t1, t2 where t1.id > 158507 and t1.id = t2.id;
> 
> That took > 84 minutes (the query was a bit longer but this is the part that 
> made the difference) after a little change the query took ~1 second:
> 
> select * from t1, t2 where t1.id > 158507 and t2.id > 158507 and t1.id = 
> t2.id;

Try posting EXPLAIN ANALYSE SELECT ... for both of those queries and 
we'll see why it's better at the second one.

-- 
   Richard Huxton
   Archonet Ltd

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