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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