Package org.apache.flink.table.legacy.sources

Interface ProjectableTableSource<T>

Type Parameters:

T - The return type of the TableSource.

@Deprecated
@Internal
public interface ProjectableTableSource<T>

Deprecated.

This interface will not be supported in the new source design around DynamicTableSource. Use SupportsProjectionPushDown instead. See FLIP-95 for more information.

Adds support for projection push-down to a TableSource.

A TableSource extending this interface is able to project the fields of the returned DataStream if it is a StreamTableSource.

Method Summary

Modifier and Type	Method	Description
TableSource<T>	projectFields(int[] fields)	Deprecated. Creates a copy of the TableSource that projects its output to the given field indexes.

Method Details

projectFields

TableSource<T> projectFields(int[] fields)

Deprecated.

Creates a copy of the TableSource that projects its output to the given field indexes. The field indexes relate to the physical produced data type (TableSource.getProducedDataType()) and not to the table schema (TableSource.getTableSchema() of the TableSource.

The table schema (TableSource.getTableSchema() of the TableSource copy must not be modified by this method, but only the produced data type (TableSource.getProducedDataType()) and the produced DataStream ( StreamTableSource#getDataStream).

If the TableSource implements the DefinedFieldMapping interface, it might be necessary to adjust the mapping as well.

IMPORTANT: This method must return a true copy and must not modify the original table source object.

Parameters:

fields - The indexes of the fields to return.

Returns:

A copy of the TableSource that projects its output.