org.apache.drill.exec.planner.logical

Interface DrillTableSelection

All Known Implementing Classes:

DruidScanSpec, FileSelection, FormatSelection, HBaseScanSpec, HiveReadEntry, HttpScanSpec, IcebergMetadataFileSelection, InfoSchemaTableType, KafkaScanSpec, KuduScanSpec, MockTableDef.MockTableSelection, MongoScanSpec, OpenTSDBScanSpec, SplunkScanSpec, SystemTable

public interface DrillTableSelection

Method Summary

Modifier and Type	Method and Description
String	digest() The digest of the selection represented by the implementation.

Method Detail

digest

String digest()

The digest of the selection represented by the implementation. The selections that accompany Tables can modify the contained dataset, e.g. a file selection can restrict to a subset of the available data and a format selection can include options that affect the behaviour of the underlying reader. Two scans will end up being considered identical during logical planning if their digests are the same so selection implementations should override this method so that exactly those scans that really are identical (in terms of the data they produce) have matching digests.

Returns:

this selection's digest, normally a string built from its properties.