org.apache.flink.table.connector.source.abilities

Interface SupportsStatisticReport

All Known Implementing Classes:

FileSystemTableSource, HiveLookupTableSource, HiveTableSource

@PublicEvolving
public interface SupportsStatisticReport

Enables to report the estimated statistics provided by the DynamicTableSource.

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 will call 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.

Method Summary

Modifier and Type	Method and Description
TableStats	reportStatistics() Returns the estimated statistics of this DynamicTableSource, else TableStats.UNKNOWN if some situations are not supported or cannot be handled.

Method Detail

reportStatistics

TableStats reportStatistics()

Returns the estimated statistics of this DynamicTableSource, else TableStats.UNKNOWN if some situations are not supported or cannot be handled.