Package org.apache.drill.exec.physical.resultSet.impl

Class UnionState

java.lang.Object

org.apache.drill.exec.physical.resultSet.impl.ContainerState

org.apache.drill.exec.physical.resultSet.impl.UnionState

All Implemented Interfaces:

VariantWriter.VariantWriterListener

public class UnionState
extends ContainerState
implements VariantWriter.VariantWriterListener

Represents the contents of a union vector (or a pseudo-union for lists). Holds the column states for the "columns" that make up the type members of the union, and implements the writer callbacks to add members to a union. This class is used when a column is a (single, non-repeated) UNION. See the ListState for when the union is used inside a LIST (repeated union) type.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	UnionState.UnionColumnState	Union or list (repeated union) column state.
static class	UnionState.UnionVectorState	Vector wrapper for a union vector.

Field Summary

Fields inherited from class org.apache.drill.exec.physical.resultSet.impl.ContainerState

loader, parentColumn, projectionSet, vectorCache

Constructor Summary

Constructors

Constructor	Description
UnionState(org.apache.drill.exec.physical.resultSet.impl.LoaderInternals events, ResultVectorCache vectorCache, ProjectionFilter projectionSet)

Method Summary

Modifier and Type	Method	Description
protected void	addColumn(ColumnState colState)
ObjectWriter	addMember(ColumnMetadata member)
ObjectWriter	addType(TypeProtos.MinorType type)
protected Collection<ColumnState>	columnStates()
int	innerCardinality()
protected boolean	isVersioned()	Reports whether this container is subject to version management.
VariantMetadata	variantSchema()
UnionVector	vector()
UnionWriterImpl	writer()

Methods inherited from class org.apache.drill.exec.physical.resultSet.impl.ContainerState

addColumn, bindColumnState, close, harvestWithLookAhead, loader, projection, rollover, startBatch, updateCardinality, vectorCache

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

UnionState

public UnionState(org.apache.drill.exec.physical.resultSet.impl.LoaderInternals events,
 ResultVectorCache vectorCache,
 ProjectionFilter projectionSet)

Method Details

writer

public UnionWriterImpl writer()

variantSchema

public VariantMetadata variantSchema()

vector

public UnionVector vector()

addType

public ObjectWriter addType(TypeProtos.MinorType type)

Specified by:

addType in interface VariantWriter.VariantWriterListener

addMember

public ObjectWriter addMember(ColumnMetadata member)

Specified by:

addMember in interface VariantWriter.VariantWriterListener

addColumn

protected void addColumn(ColumnState colState)

Specified by:

addColumn in class ContainerState

columnStates

protected Collection<ColumnState> columnStates()

Specified by:

columnStates in class ContainerState

innerCardinality

public int innerCardinality()

Specified by:

innerCardinality in class ContainerState

isVersioned

protected boolean isVersioned()

Description copied from class: ContainerState

Reports whether this container is subject to version management. Version management adds columns to the output container at harvest time based on whether they should appear in the output batch.

Specified by:

isVersioned in class ContainerState

Returns:

true if versioned