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Archives of the TeradataForum
Message Posted: Sat, 12 Jun 2004 @ 10:45:53 GMT
Subj: | | Re: Performance Improvement on this Query without Collecting Statistics |
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From: | | Victor Sokovin |
| The first thing you should do is get and analyze the explain. Anything you do before that is trial and error based on theory and
speculation. It is much easier to solve a problem when you know, in detail, what the problem is. | |
I don't think one would get a lot of insight out of analysis of explains only in cases like the one discussed here, i.e., conversion of
daily figures into the weekly aggregates with the volumes as described by the OP. That's the process which is in place in many companies and the
problems and their resolutions seem to be very similar. Usually it is either a purchase of more hardware (often preceded by months of analysis and
ever deteriorating performance) or rewriting the query in a more economical way. The second approach often leads to immediate visible results. I
think some of the suggestions made in the thread are based on the authors' experience with the second approach.
Regards,
Victor
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