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Message Posted: Mon, 11 Jul 2005 @ 09:31:52 GMT

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<-- Anonymously Posted: Monday, July 11, 2005 00:11 -->

Hi,

The TD optimizer genereates the plan without the knowledge of the bind variables. Then at the APPLY step, binds the variables with the values. -- Is this a correct understanding?

If so, how does the optimizer decide on plans when there is a data skew? Lets say theres a column with a NUSI. It is strongly selecetive for all values except for a specific value say X for which theres a spike. How can the optmizer take a decision to use the NUSI or go for an FTS without knowing what the value is?

The Oracle optmizer has a feature called "BIND PEEKING" which is specifically designed for this kind of scenarios.

Is my understanding of TD optmizer correct? Pls correct me if am wrong!

Thanks

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