org.apache.flink.table.sources

Interface PartitionableTableSource

@Experimental
public interface PartitionableTableSource

An interface for partitionable TableSource.

A PartitionableTableSource can exclude partitions from reading, which includes skipping the metadata. This is especially useful when there are thousands of partitions in a table.

A partition is represented as a Map<String, String> which maps from partition field name to partition value. Since the map is NOT ordered, the correct order of partition fields should be obtained via getPartitionFieldNames().

Method Summary

Modifier and Type	Method and Description
TableSource	applyPartitionPruning(List<Map<String,String>> remainingPartitions) Applies the remaining partitions to the table source.
List<String>	getPartitionFieldNames() Gets the partition field names of the table.
List<Map<String,String>>	getPartitions() Returns all the partitions of this PartitionableTableSource.

Method Detail

getPartitions

List<Map<String,String>> getPartitions()

Returns all the partitions of this PartitionableTableSource.

getPartitionFieldNames

List<String> getPartitionFieldNames()

Gets the partition field names of the table. The partition field names should be sorted in a strict order, i.e. they have the order as specified in the PARTITION statement in DDL. This should be an empty set if the table is not partitioned.

All the partition fields should exist in the TableSink.getTableSchema().

Returns:

partition field names of the table, empty if the table is not partitioned.

applyPartitionPruning

TableSource applyPartitionPruning(List<Map<String,String>> remainingPartitions)

Applies the remaining partitions to the table source. The remainingPartitions is the remaining partitions of getPartitions() after partition pruning applied.

After trying to apply partition pruning, we should return a new TableSource instance which holds all pruned-partitions.

Parameters:

remainingPartitions - Remaining partitions after partition pruning applied.

Returns:

A new cloned instance of TableSource holds all pruned-partitions.