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Archives of the TeradataForum
Message Posted: Tue, 25 Aug 2009 @ 13:40:43 GMT
| Subj: | | Re: Parsing of SQL in teradata |
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| From: | | Anomy Anom |
<-- Anonymously Posted: Tuesday, August 25, 2009 09:37 -->
The Teradata optimizer may modify the order of evaluation of WHERE conditions, and the JOIN order, in any way that is guaranteed to produce the
same result as the original query. If you look at the EXPLAIN, you will often find that some WHERE conditions are applied prior to or during a
join step and others after. It all depends on what the optimizer judges to be lowest cost.
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