net.sf.farrago.fennel.rel
Class FennelBernoulliSamplingRel

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