org.apache.flink.table.connector

Interface ParallelismProvider

All Known Subinterfaces:

DataStreamScanProvider, DataStreamSinkProvider, InputFormatProvider, OutputFormatProvider, SinkFunctionProvider, SinkProvider, SinkV2Provider, SourceFunctionProvider, SourceProvider, TransformationScanProvider

@PublicEvolving
public interface ParallelismProvider

Parallelism provider for other connector providers. It allows to express a custom parallelism for the connector runtime implementation. Otherwise, the parallelism is determined by the planner.

Method Summary

Modifier and Type	Method and Description
default Optional<Integer>	getParallelism() Returns the parallelism for this instance.

Method Detail

getParallelism

default Optional<Integer> getParallelism()

Returns the parallelism for this instance.

The parallelism denotes how many parallel instances of a source or sink will be spawned during the execution.

Enforcing a different parallelism for sources/sinks might mess up the changelog if the output/input is not ChangelogMode.insertOnly(). Therefore, a primary key is required by which the output/input will be shuffled after/before records leave/enter the ScanTableSource.ScanRuntimeProvider/DynamicTableSink.SinkRuntimeProvider implementation.

Returns:

empty if the connector does not provide a custom parallelism, then the planner will decide the number of parallel instances by itself.