A Dimecres 21 Maig 2008, Richard Huxton va escriure:
> 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.
Right, attached an example of such a difference.