Examine the parameters for your database instance:...
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Examine the parameters for your database instance: Which three statements are true about the process of automatic optimization by using cardinality feedback?()

发布日期:2020-04-10

A.The optimizer automatically changes a plan during subsequent execution of a SQL statement if there is a huge difference in optimizer estimates and execution statistics.

B.The optimizer can re optimize a query only once using cardinality feedback.

C.The optimizer enables monitoring for cardinality feedback after the first execution of a query.

D.The optimizer does not monitor cardinality feedback if dynamic sampling and multicolumn statistics are enabled.

E.After the optimizer identifies a query as a re-optimization candidate, statistics collected by the collectors are submitted to the optimizer.

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