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Home -> Community -> Mailing Lists -> Oracle-L -> Re[2]: A Cure for Madness
Sunday, August 29, 2004, 5:29:08 PM, Wolfgang Breitling (breitliw_at_centrexcc.com) wrote:
WB> That's not what he says in the article. There he gives an "unequivocal no"
WB> to the question whether it is valid to rewrite the query.
Date does not say that optimization, including merging, can't happen. Optimization is fine. I've never been opposed even to merging, so long as it is done in a way that preserves the "as if" results, meaning that the results still must be "as if" the subquery had been materialized, even though, in fact, it has not been. This is a reachable goal.
What Date says in his article is that the results of the optimization do not match the results that you get by following the conceptual process described in the language standard, and thus the optimization is flawed.
Best regards,
Jonathan Gennick --- Brighten the corner where you are http://Gennick.com * 906.387.1698 * mailto:jonathan@gennick.com
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