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From: Albert Cervera Areny <albert@sedifa.com>
Organization: Sedifa, S.L.
To: pgsql-performance@postgresql.org
Subject: Posible planner improvement?
Date: Wed, 21 May 2008 12:28:47 +0200
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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;

The change is pretty simple and it seems (note I don't have a clue on how the 
planner works) it'd be possible for the planner to make this assumption 
itself. Do you think it is really feasible/appropiate?