net.sf.farrago.fennel.rel
Class FennelPullCorrelatorRel

java.lang.Object
  org.eigenbase.rel.AbstractRelNode
      net.sf.farrago.fennel.rel.FennelDoubleRel
          net.sf.farrago.fennel.rel.FennelPullCorrelatorRel

All Implemented Interfaces:

Cloneable, FennelRel, RelNode

public class FennelPullCorrelatorRel
extends FennelDoubleRel

FennelPullCorrelatorRel is the relational expression corresponding to a correlation between two streams implemented inside of Fennel.

Since:

Feb 1, 2005

Version:

$Id: //open/dev/farrago/src/net/sf/farrago/fennel/rel/FennelPullCorrelatorRel.java#2 $

Author:

Wael Chatila

Field Summary

protected List<CorrelatorRel.Correlation>

correlations

Fields inherited from class net.sf.farrago.fennel.rel.FennelDoubleRel

left, right

Fields inherited from class org.eigenbase.rel.AbstractRelNode

digest, id, rowType, traits

Fields inherited from interface net.sf.farrago.query.FennelRel

FENNEL_EXEC_CONVENTION

Fields inherited from interface org.eigenbase.rel.RelNode

emptyArray

Constructor Summary

FennelPullCorrelatorRel(RelOptCluster cluster, RelNode left, RelNode right, List<CorrelatorRel.Correlation> correlations)
Creates a Correlator.

Method Summary

FennelPullCorrelatorRel	clone() Clones this RelNode.
RelOptCost	computeSelfCost(RelOptPlanner planner) Returns the cost of this plan (not including children).
protected RelDataType	deriveRowType()
void	explain(RelOptPlanWriter pw)
double	getRows() Returns an estimate of the number of rows this relational expression will return.
FemExecutionStreamDef	toStreamDef(FennelRelImplementor implementor) Converts this relational expression to FemExecutionStreamDef form.

Methods inherited from class net.sf.farrago.fennel.rel.FennelDoubleRel

getCollations, getFarragoTypeFactory, getInputs, implementFennelChild, replaceInput

Methods inherited from class org.eigenbase.rel.AbstractRelNode

childrenAccept, cloneTraits, collectVariablesSet, collectVariablesUsed, computeDigest, getChildExps, getCluster, getCollationList, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getOrCreateCorrelVariable, getQuery, getRelTypeName, getRowType, getTable, getTraits, getVariablesStopped, inheritTraitsFrom, isAccessTo, isDistinct, isValid, onRegister, recomputeDigest, register, registerCorrelVariable, setCorrelVariable, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eigenbase.rel.RelNode

childrenAccept, collectVariablesSet, collectVariablesUsed, getChildExps, getCluster, getCollationList, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getOrCreateCorrelVariable, getQuery, getRelTypeName, getRowType, getTable, getTraits, getVariablesStopped, isAccessTo, isDistinct, isValid, onRegister, recomputeDigest, registerCorrelVariable, setCorrelVariable

Field Detail

correlations

protected final List<CorrelatorRel.Correlation> correlations

Constructor Detail

FennelPullCorrelatorRel

public FennelPullCorrelatorRel(RelOptCluster cluster,
                               RelNode left,
                               RelNode right,
                               List<CorrelatorRel.Correlation> correlations)

Creates a Correlator.

Parameters:

cluster - RelOptCluster this relational expression belongs to

left - left input relational expression

right - right input relational expression

correlations - set of expressions to set as variables each time a row arrives from the left input

Method Detail

clone

public FennelPullCorrelatorRel clone()

Description copied from interface: RelNode

Clones this RelNode.

Traits of the RelNode must be explicitly cloned, using AbstractRelNode.inheritTraitsFrom(AbstractRelNode), as the RelNode may have traits of which it has no knowledge. Example implementation:

     public MyRelNode clone()
     {
         MyRelNode clone = new MyRelNode(...);
         clone.inheritTraitsFrom(this);
         return clone;
     }
 

N.B.: This method must be overridden whenever an existing, concrete RelNode is extended. Otherwise, calling clone() will produce a differently typed RelNode, resulting in invalid or incorrect query plans.

Specified by:

clone in interface RelNode

Specified by:

clone in class AbstractRelNode

Returns:

a clone of this RelNode

explain

public void explain(RelOptPlanWriter pw)

Specified by:

explain in interface RelNode

Overrides:

explain in class AbstractRelNode

computeSelfCost

public RelOptCost computeSelfCost(RelOptPlanner planner)

Description copied from interface: RelNode

Returns the cost of this plan (not including children). The base implementation throws an error; derived classes should override.

NOTE jvs 29-Mar-2006: Don't call this method directly. Instead, use RelMetadataQuery.getNonCumulativeCost(org.eigenbase.rel.RelNode), which gives plugins a chance to override the rel's default ideas about cost.

Specified by:

computeSelfCost in interface RelNode

Overrides:

computeSelfCost in class AbstractRelNode

getRows

public double getRows()

Description copied from interface: RelNode

Returns an estimate of the number of rows this relational expression will return.

NOTE jvs 29-Mar-2006: Don't call this method directly. Instead, use RelMetadataQuery.getRowCount(org.eigenbase.rel.RelNode), which gives plugins a chance to override the rel's default ideas about row count.

Specified by:

getRows in interface RelNode

Overrides:

getRows in class AbstractRelNode

deriveRowType

protected RelDataType deriveRowType()

Overrides:

deriveRowType in class FennelDoubleRel

toStreamDef

public FemExecutionStreamDef toStreamDef(FennelRelImplementor implementor)

Description copied from interface: FennelRel

Converts this relational expression to FemExecutionStreamDef form. In the process, the relational expression will almost certainly call FennelRelImplementor.visitFennelChild(net.sf.farrago.query.FennelRel, int) on each of its children.

Parameters:

implementor - for generating Java code

Returns:

generated FemExecutionStreamDef