com.metamatrix.query.processor.relational
Class MergeJoinStrategy

java.lang.Object
  com.metamatrix.query.processor.relational.JoinStrategy
      com.metamatrix.query.processor.relational.MergeJoinStrategy

Direct Known Subclasses:

NestedLoopJoinStrategy, PartitionedSortJoin

public class MergeJoinStrategy
extends JoinStrategy

MergeJoinStrategy supports generalized Full, Left Outer, and Inner Joins (containing non-equi join criteria) as long as there is at least one equi-join criteria Additionally supports Semi and Anti-Semi Joins. These too allow for generalized non-equi join criteria. TODO: when there is no non-equi join criteria matching duplicates from the outer side can be output immediately TODO: semi joins should only output left tuples Support for Intersect and Except is controlled by the grouping flag, which changes comparisons to check for null equality.

Nested Class Summary

static class

MergeJoinStrategy.SortOption

Field Summary

protected MergeJoinStrategy.SortOption	processingSortLeft
protected MergeJoinStrategy.SortOption	processingSortRight
protected MergeJoinStrategy.SortOption	sortLeft
protected MergeJoinStrategy.SortOption	sortRight

Fields inherited from class com.metamatrix.query.processor.relational.JoinStrategy

joinNode, leftSource, rightSource

Constructor Summary

MergeJoinStrategy(MergeJoinStrategy.SortOption sortLeft, MergeJoinStrategy.SortOption sortRight, boolean grouping)

Method Summary

java.lang.Object	clone()
void	close()
protected int	compare(java.util.List leftProbe, java.util.List rightProbe, int[] leftExpressionIndecies, int[] rightExpressionIndecies)
protected boolean	compareToPrevious(com.metamatrix.query.processor.relational.SourceState target)
java.lang.String	getName()
void	initialize(JoinNode joinNode)
protected void	loadLeft()
protected java.util.List	nextTuple()
protected void	postLoadLeft()
protected void	postLoadRight()
void	setProcessingSortRight(boolean processingSortRight)
protected void	sortRight()
java.lang.String	toString()

Methods inherited from class com.metamatrix.query.processor.relational.JoinStrategy

loadRight, outputTuple

Methods inherited from class java.lang.Object

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

Field Detail

sortLeft

protected MergeJoinStrategy.SortOption sortLeft

sortRight

protected MergeJoinStrategy.SortOption sortRight

processingSortLeft

protected MergeJoinStrategy.SortOption processingSortLeft

processingSortRight

protected MergeJoinStrategy.SortOption processingSortRight

Constructor Detail

MergeJoinStrategy

public MergeJoinStrategy(MergeJoinStrategy.SortOption sortLeft,
                         MergeJoinStrategy.SortOption sortRight,
                         boolean grouping)

Method Detail

clone

public java.lang.Object clone()

Specified by:

clone in class JoinStrategy

See Also:

JoinStrategy.clone()

initialize

public void initialize(JoinNode joinNode)
                throws MetaMatrixComponentException

Overrides:

initialize in class JoinStrategy

Throws:

MetaMatrixComponentException

See Also:

JoinStrategy.initialize(com.metamatrix.query.processor.relational.JoinNode)

close

public void close()
           throws TupleSourceNotFoundException,
                  MetaMatrixComponentException

Overrides:

close in class JoinStrategy

Throws:

TupleSourceNotFoundException

MetaMatrixComponentException

See Also:

JoinStrategy.close()

nextTuple

protected java.util.List nextTuple()
                            throws MetaMatrixComponentException,
                                   CriteriaEvaluationException,
                                   MetaMatrixProcessingException

Specified by:

nextTuple in class JoinStrategy

Throws:

MetaMatrixComponentException

CriteriaEvaluationException

MetaMatrixProcessingException

compareToPrevious

protected boolean compareToPrevious(com.metamatrix.query.processor.relational.SourceState target)
                             throws MetaMatrixComponentException,
                                    MetaMatrixProcessingException

Throws:

MetaMatrixComponentException

MetaMatrixProcessingException

compare

protected int compare(java.util.List leftProbe,
                      java.util.List rightProbe,
                      int[] leftExpressionIndecies,
                      int[] rightExpressionIndecies)

loadLeft

protected void loadLeft()
                 throws MetaMatrixComponentException,
                        MetaMatrixProcessingException

Overrides:

loadLeft in class JoinStrategy

Throws:

MetaMatrixComponentException

MetaMatrixProcessingException

See Also:

JoinStrategy.loadLeft()

postLoadLeft

protected void postLoadLeft()
                     throws MetaMatrixComponentException,
                            MetaMatrixProcessingException

Overrides:

postLoadLeft in class JoinStrategy

Throws:

MetaMatrixComponentException

MetaMatrixProcessingException

postLoadRight

protected void postLoadRight()
                      throws MetaMatrixComponentException,
                             MetaMatrixProcessingException

Overrides:

postLoadRight in class JoinStrategy

Throws:

MetaMatrixComponentException

MetaMatrixProcessingException

sortRight

protected void sortRight()
                  throws MetaMatrixComponentException,
                         TupleSourceNotFoundException,
                         BlockedOnMemoryException

Throws:

MetaMatrixComponentException

TupleSourceNotFoundException

BlockedOnMemoryException

setProcessingSortRight

public void setProcessingSortRight(boolean processingSortRight)

getName

public java.lang.String getName()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

See Also:

Object.toString()