net.sf.farrago.fennel.rel
Class FennelMergeRel

java.lang.Object
  extended by org.eigenbase.rel.AbstractRelNode
      extended by net.sf.farrago.fennel.rel.FennelMultipleRel
          extended by net.sf.farrago.fennel.rel.FennelMergeRel
All Implemented Interfaces:
Cloneable, FennelRel, RelNode

 class FennelMergeRel
extends FennelMultipleRel

FennelMergeRel represents the Fennel implementation of UNION ALL.

Version:
$Id: //open/dev/farrago/src/net/sf/farrago/fennel/rel/FennelMergeRel.java#1 $
Author:
John V. Sichi

Field Summary
 
Fields inherited from class net.sf.farrago.fennel.rel.FennelMultipleRel
inputs
 
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
FennelMergeRel(RelOptCluster cluster, RelNode[] inputs)
          Creates a new FennelMergeRel object.
 
Method Summary
 FennelMergeRel 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.FennelMultipleRel
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
 

Constructor Detail

FennelMergeRel

FennelMergeRel(RelOptCluster cluster,
               RelNode[] inputs)
Creates a new FennelMergeRel object.

Parameters:
cluster - RelOptCluster for this rel
inputs - array of inputs
Method Detail

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

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

deriveRowType

protected RelDataType deriveRowType()
Overrides:
deriveRowType in class FennelMultipleRel

clone

public FennelMergeRel 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

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