Re: bug with UNION ALL in subquery in 7.1.3.4.0
Date: 28 Jan 1995 00:30:57 GMT
Message-ID: <3gc381$ipj_at_dcsun4.us.oracle.com>
l.carl.pedersen_at_dartmouth.edu (L Carl Pedersen) writes:
|> UNION ALL sometimes causes wrong answers when used in the subquery of an
|> IN predicate.
|>
|> I suspect this syntax is being incorrectly converted to a join.
You are basically correct. The problem only shows up if a UNION ALL appears as a subquery in an IN clause. This is bug #228071. It will be fixed in 7.1.5. I believe the fix would involve doing a sort of the results of the UNION ALL to remove the duplicates before doing the join. This would negate any performance gain you were hoping to achieve by avoiding the sort.
Hope this helps.
Roderick Manalac
Oracle Corporation
DISCLAIMER: My opinions not necessarily influenced by my employers or other addictive substances. Received on Sat Jan 28 1995 - 01:30:57 CET