org.apache.spark.sql.sources.v2

Interface ReadSupport

All Superinterfaces:

DataSourceV2

@InterfaceStability.Evolving
public interface ReadSupport
extends DataSourceV2

A mix-in interface for DataSourceV2. Data sources can implement this interface to provide data reading ability and scan the data from the data source.

Method Summary

Modifier and Type	Method and Description
DataSourceReader	createReader(DataSourceOptions options) Creates a DataSourceReader to scan the data from this data source.
default DataSourceReader	createReader(StructType schema, DataSourceOptions options) Creates a DataSourceReader to scan the data from this data source.

Method Detail

createReader

default DataSourceReader createReader(StructType schema,
                                      DataSourceOptions options)

Creates a DataSourceReader to scan the data from this data source. If this method fails (by throwing an exception), the action will fail and no Spark job will be submitted.

Parameters:

schema - the user specified schema.

options - the options for the returned data source reader, which is an immutable case-insensitive string-to-string map. By default this method throws UnsupportedOperationException, implementations should override this method to handle user specified schema.

createReader

DataSourceReader createReader(DataSourceOptions options)

Creates a DataSourceReader to scan the data from this data source. If this method fails (by throwing an exception), the action will fail and no Spark job will be submitted.

Parameters:

options - the options for the returned data source reader, which is an immutable case-insensitive string-to-string map.