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Archives of the TeradataForum
Message Posted: Wed, 02 Apr 2003 @ 18:18:32 GMT
| Subj: | | Re: V2R5.0 release summary terms |
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| From: | | Loomis, Ernie |
Block optimization in the Release 5 context refers to the way the optimizer works. Previously the optimizer looked at subqueries,
derived tables, views as separate "blocks" of work and optimized independently. You might have a highly selective WHERE in the main
query that would reduce the data spooled in the subquery, but the subquery "block" optimization did not recognize that. With R5, the
full query is examined for possible cost savings
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