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Archives of the TeradataForum
Message Posted: Fri, 31 Oct 2003 @ 14:23:50 GMT
Subj: | | Re: CPU for string operations |
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From: | | Meade, Cornelius |
Agreed...Use of concatenation and other string manipulation functions in the where/join clause can often cause the optimizer to elect to
invalidate the use of SI's that might have benefited a differently structured but logically equivalent transaction and choose to perform a
full table scan.
It is also worth noting that while not always the case, I often find that if the business users are doing a lot of this then the
schema/data model in effect may not accurately reflect the real business needs in some way, particularly if you are dealing with something
that has been denormalized. Conversely, this type of thing might be reason to do a bit of denormalizing....
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