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Message Posted: Tue, 13 Jun 2000 @ 21:22:56 GMT


     
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Subj:   Re: Hot Amp
 
From:   Jim Downey

Hello, it sounds as if something you are doing is causing the data to redistribute using the date column with the low cardinality as the primary index. For example, the creation of a derived table. Once the data starts to move, it is moved from the amp with the UPI to the hot amp where the only value it can hash on is null or 99/01/24.

Does your explain tell you when it redistributes and can you code around it?

Although the SQL is not as elegant, I sometimes find it is easier to debug complex queries by breaking them into their component parts and test each answer set using temp tables.

That might help isolate and identify the cure for a problematic query. I hope that helps.

Jim



     
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