@PublicEvolving public interface SupportsStatisticReport
Statistics are one of the most important inputs to the optimizer cost model, which will generate the most effective execution plan with the lowest cost among all considered candidate plans.
This interface is used to compensate for the missing of statistics in the catalog. The planner
reportStatistics() method when the planner detects the statistics from catalog
is unknown. Therefore, the method will be executed as needed.
Note: This method is called at plan optimization phase, the implementation of this interface should be as light as possible, but more complete information.
|Modifier and Type||Method and Description|
Returns the estimated statistics of this
TableStats.UNKNOWNif some situations are not supported or cannot be handled.
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