net.sf.farrago.fennel.rel
Class FennelBufferRel

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

All Implemented Interfaces:

Cloneable, FennelRel, RelNode

Direct Known Subclasses:

FennelMultiUseBufferRel

 class FennelBufferRel
extends FennelSingleRel

FennelBufferRel represents the Fennel implementation of a buffering stream. product.

Version:

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

Author:

Zelaine Fong

Field Summary

protected boolean	inMemory
protected boolean	multiPass

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

FennelBufferRel(RelOptCluster cluster, RelNode child, boolean inMemory, boolean multiPass)
Creates a new FennelBufferRel object.

Method Summary

FennelBufferRel	clone() Clones this RelNode.
RelOptCost	computeSelfCost(RelOptPlanner planner) Returns the cost of this plan (not including children).
void	explain(RelOptPlanWriter pw)
double	getRows() Returns an estimate of the number of rows this relational expression will return.
(package private) boolean	isInMemory()
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, 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, getInputs, getOrCreateCorrelVariable, getQuery, getRelTypeName, getRowType, getTable, getTraits, getVariablesStopped, isAccessTo, isDistinct, isValid, onRegister, recomputeDigest, registerCorrelVariable, replaceInput, setCorrelVariable

Field Detail

inMemory

protected boolean inMemory

multiPass

protected boolean multiPass

Constructor Detail

FennelBufferRel

public FennelBufferRel(RelOptCluster cluster,
                       RelNode child,
                       boolean inMemory,
                       boolean multiPass)

Creates a new FennelBufferRel object.

Parameters:

cluster - RelOptCluster for this rel

child - child input

inMemory - true if the buffering needs to be done only in memory

multiPass - true if the buffer output will be read multiple times

Method Detail

isInMemory

boolean isInMemory()

Returns:

true if the buffering needs to be done only in memory

clone

public FennelBufferRel 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

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 SingleRel

explain

public void explain(RelOptPlanWriter pw)

Specified by:

explain in interface RelNode

Overrides:

explain 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