Presenter: Maria Colgan, Master Product Manager, Oracle Corporation
Date: 03/28/2019
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During the optimization of a SQL statement the Optimizer relies heavily on statistics to estimate the number of rows produced by each of the SQL operators. The quality of the statistics for the objects referenced in the statement greatly affects the quality of the plan. Statistics maintenance is a challenge all DBAs must face in order to prevent execution plan from becoming suboptimal. This presentation includes information on the features introduced in 11g and 12c to improve the quality and efficiency of statistics gathering, as well as strategies for managing statistics, include how to use dynamic sampling and when, and how, to manually set statistics directly versus collecting them.