Without actually knowing what you're really trying to achieve (as the
two queries are markedly different in what would be produced)... It
seems the second query should be an "INNER JOIN" - perhaps?

Seeing the EXPLAIN output of your original queries and the second one
with a "INNER JOIN" could be helpful, along some sort of explanation of
what your objective of each query is...along a brief description of the
columns/fields and their relationship(s) to the tables being joined...if
possible.


Regards,
David

-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Anthony
Youngman
Sent: Monday, 21 July 2008 7:49 PM
To: '[email protected]'
Subject: RE: [U2] Strange SQL query optimisation ...

Thanks.

If I add the no.optimize keyword, it changes all joins to an "outer
cartesian join". So that's even worse ... (I haven't tried actually
running it :-)

If a LEFT JOIN and LEFT OUTER JOIN  are the same thing, that adds
another little oddity to the mix :-) Why is the optimiser using both
terminologies when the input uses just one? :-) Not that that's
important unless it gives IBM's engineers a clue ...

Cheers,
Wol
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