org.apache.drill.exec.physical.impl.scan.project

Interface ReaderLevelProjection.ReaderProjectionResolver

All Known Implementing Classes:

ColumnsArrayManager, ImplicitColumnManager

Enclosing class:

ReaderLevelProjection

public static interface ReaderLevelProjection.ReaderProjectionResolver

Reader-level projection is customizable. Implement this interface, and add an instance to the scan orchestrator, to perform custom mappings from unresolved columns (perhaps of an extension-specified type) to final projected columns. The metadata manager, for example, implements this interface to map metadata columns.

Method Summary

Modifier and Type	Method and Description
boolean	resolveColumn(ColumnProjection col, ResolvedTuple tuple, TupleMetadata tableSchema)
void	startResolution()

Method Detail

startResolution

void startResolution()

resolveColumn

boolean resolveColumn(ColumnProjection col,
                      ResolvedTuple tuple,
                      TupleMetadata tableSchema)