org.modeshape.jcr.query.process

Class MergeJoinComponent

java.lang.Object

org.modeshape.jcr.query.process.ProcessingComponent

org.modeshape.jcr.query.process.JoinComponent

org.modeshape.jcr.query.process.MergeJoinComponent

@Immutable
public class MergeJoinComponent
extends JoinComponent

Create a processing component that performs a merge-join algorithm. This algorithm only makes sense for equi-joins, child-node joins, and same-node joins.

Note that it is required that the left and right processing components (where this component gets its results) must already be properly sorted and have had duplicates removed.

Nested Class Summary

Nested classes/interfaces inherited from class org.modeshape.jcr.query.process.JoinComponent

JoinComponent.Joinable, JoinComponent.TupleMerger, JoinComponent.ValueSelector

Nested classes/interfaces inherited from class org.modeshape.jcr.query.process.ProcessingComponent

ProcessingComponent.DynamicOperation

Field Summary

Fields inherited from class org.modeshape.jcr.query.process.JoinComponent

LOCATION_COMPARATOR

Constructor Summary

Constructors

Constructor and Description
MergeJoinComponent(QueryContext context, ProcessingComponent left, ProcessingComponent right, ChildNodeJoinCondition condition, JoinType joinType)
MergeJoinComponent(QueryContext context, ProcessingComponent left, ProcessingComponent right, EquiJoinCondition condition, JoinType joinType)
MergeJoinComponent(QueryContext context, ProcessingComponent left, ProcessingComponent right, SameNodeJoinCondition condition, JoinType joinType)

Method Summary

Methods

Modifier and Type	Method and Description
List<Object[]>	execute() Execute this stage of processing and return the resulting tuples that each conform to the columns.
protected boolean	isSameTuple(QueryResults.Columns columns, Object[] tuple1, Object[] tuple2)

Methods inherited from class org.modeshape.jcr.query.process.JoinComponent

arrayAwareComparator, comparatorFor, createMerger, getJoinCondition, getJoinType, joinableFor, left, leftColunns, right, rightColumns, valueSelectorFor

Methods inherited from class org.modeshape.jcr.query.process.ProcessingComponent

close, createDynamicOperation, createSortComparator, emptyTuples, getColumns, getContext, getLocationIndexes, problems

Methods inherited from class java.lang.Object

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

Constructor Detail

MergeJoinComponent

public MergeJoinComponent(QueryContext context,
                  ProcessingComponent left,
                  ProcessingComponent right,
                  EquiJoinCondition condition,
                  JoinType joinType)

MergeJoinComponent

public MergeJoinComponent(QueryContext context,
                  ProcessingComponent left,
                  ProcessingComponent right,
                  ChildNodeJoinCondition condition,
                  JoinType joinType)

MergeJoinComponent

public MergeJoinComponent(QueryContext context,
                  ProcessingComponent left,
                  ProcessingComponent right,
                  SameNodeJoinCondition condition,
                  JoinType joinType)

Method Detail

execute

public List<Object[]> execute()

Description copied from class: ProcessingComponent

Execute this stage of processing and return the resulting tuples that each conform to the columns.

Specified by:

execute in class ProcessingComponent

Returns:

the list of tuples, where each tuple corresonds to the columns; never null

isSameTuple

protected final boolean isSameTuple(QueryResults.Columns columns,
                  Object[] tuple1,
                  Object[] tuple2)