"Pascal Tufenkji" <ptufenkji@usj.edu.lb> writes:
> Actually I'm using PostgreSQL 8.2.4
Well, in that case the answer to $SUBJECT is "Yes". Please update to
something reasonably current --- at least 8.2.7, which contains the most
recent fix for join planning logic according to a quick scan of the
CVS logs. (8.2.11 is the most recent release in that branch.)
If you can still reproduce the problem on 8.2.latest then it would be
worth investigating further; but right at the moment I think it's a
good bet that this is the same as one of the already-identified bugs
in outer join planning.
regards, tom lane