A while ago some of us were having a discussion as a result of
somebody's "not in" query. A few people proposed solutions that had explicit
co-related subqueries in them, and reported better results than the "not-in"
This confused me, so I finally got back to some notes I had taken from a
meeting with an Oracle consultant, and found out the Oracle treats
"not-in" statements as if they were co-related subqueries! Now, I don't
know what exactly "treats" means, but I'm guessing it means that the
sub-query is re-evaluated per each row in the outer query?
Does anyone know why this would be implemented this way?
Dave
David B Erickson, Project Leader *
McHugh Freeman * "YIP YIP YIP YIP YIP YIP YIP YIP YIP"
erickson_at_mfa.com * -Dino
Received on Tue May 23 1995 - 00:00:00 CEST
