net.sf.farrago.fennel.rel
Class FennelBernoulliSamplingRel

java.lang.Object
  org.eigenbase.rel.AbstractRelNode
      org.eigenbase.rel.SingleRel
          net.sf.farrago.fennel.rel.FennelSingleRel
              net.sf.farrago.fennel.rel.FennelBernoulliSamplingRel

All Implemented Interfaces:

Cloneable, FennelRel, RelNode

public class FennelBernoulliSamplingRel
extends FennelSingleRel

FennelBernoulliSamplingRel implements Bernoulli-style table sampling using a generic Fennel XO.

Author:

Stephan Zuercher

Field Summary

private RelOptSamplingParameters

samplingParams

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

FennelBernoulliSamplingRel(RelOptCluster cluster, RelNode child, RelOptSamplingParameters samplingParams)

Method Summary

RelNode	clone() Clones this RelNode.
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.FennelSingleRel

getCollations, getFarragoTypeFactory, implementFennelChild

Methods inherited from class org.eigenbase.rel.SingleRel

childrenAccept, deriveRowType, getChild, getInputs, replaceInput

Methods inherited from class org.eigenbase.rel.AbstractRelNode

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

Field Detail

samplingParams

private final RelOptSamplingParameters samplingParams

Constructor Detail

FennelBernoulliSamplingRel

public FennelBernoulliSamplingRel(RelOptCluster cluster,
                                  RelNode child,
                                  RelOptSamplingParameters samplingParams)

Method Detail

clone

public RelNode 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 SingleRel

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 SingleRel

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