Package org.apache.calcite.plan.hep

Class HepRelVertex

java.lang.Object

org.apache.calcite.rel.AbstractRelNode

org.apache.calcite.plan.hep.HepRelVertex

All Implemented Interfaces:

java.lang.Cloneable, RelOptNode, RelNode

public class HepRelVertex
extends AbstractRelNode

HepRelVertex wraps a real RelNode as a vertex in a DAG representing the entire query expression.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.calcite.rel.RelNode

RelNode.Context

Field Summary

Fields

Modifier and Type	Field	Description
private RelNode	currentRel	Wrapped rel currently chosen for implementation of expression.

Fields inherited from class org.apache.calcite.rel.AbstractRelNode

digest, id, rowType, traitSet

Constructor Summary

Constructors

Constructor	Description
HepRelVertex(RelNode rel)

Method Summary

Modifier and Type	Method	Description
protected java.lang.String	computeDigest()	Computes the digest.
RelOptCost	computeSelfCost(RelOptPlanner planner, RelMetadataQuery mq)	Returns the cost of this plan (not including children).
RelNode	copy(RelTraitSet traitSet, java.util.List<RelNode> inputs)	Creates a copy of this relational expression, perhaps changing traits and inputs.
protected RelDataType	deriveRowType()
double	estimateRowCount(RelMetadataQuery mq)	Returns an estimate of the number of rows this relational expression will return.
void	explain(RelWriter pw)	Describes the inputs and attributes of this relational expression.
RelNode	getCurrentRel()
(package private) void	replaceRel(RelNode newRel)	Replaces the implementation for this expression with a new one.

Methods inherited from class org.apache.calcite.rel.AbstractRelNode

accept, accept, childrenAccept, collectVariablesSet, collectVariablesUsed, computeSelfCost, explainTerms, getChildExps, getCluster, getCollationList, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getInputs, getQuery, getRelTypeName, getRows, getRowType, getTable, getTraitSet, getVariablesSet, getVariablesStopped, isDistinct, isKey, isValid, isValid, metadata, onRegister, recomputeDigest, register, replaceInput, sole, toString

Methods inherited from class java.lang.Object

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

Field Detail

currentRel

private RelNode currentRel

Wrapped rel currently chosen for implementation of expression.

Constructor Detail

HepRelVertex

HepRelVertex(RelNode rel)

Method Detail

explain

public void explain(RelWriter pw)

Description copied from interface: RelNode

Describes the inputs and attributes of this relational expression. Each node should call super.explain, then call the RelWriterImpl.input(String, RelNode) and RelWriterImpl.item(String, Object) methods for each input and attribute.

Specified by:

explain in interface RelNode

Overrides:

explain in class AbstractRelNode

Parameters:

pw - Plan writer

copy

public RelNode copy(RelTraitSet traitSet,
                    java.util.List<RelNode> inputs)

Description copied from interface: RelNode

Creates a copy of this relational expression, perhaps changing traits and inputs.

Sub-classes with other important attributes are encouraged to create variants of this method with more parameters.

Specified by:

copy in interface RelNode

Overrides:

copy in class AbstractRelNode

Parameters:

traitSet - Trait set

inputs - Inputs

Returns:

Copy of this relational expression, substituting traits and inputs

computeSelfCost

public RelOptCost computeSelfCost(RelOptPlanner planner,
                                  RelMetadataQuery mq)

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.apache.calcite.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

Parameters:

planner - Planner for cost calculation

mq - Metadata query

Returns:

Cost of this plan (not including children)

estimateRowCount

public double estimateRowCount(RelMetadataQuery mq)

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.apache.calcite.rel.RelNode), which gives plugins a chance to override the rel's default ideas about row count.

Specified by:

estimateRowCount in interface RelNode

Overrides:

estimateRowCount in class AbstractRelNode

Parameters:

mq - Metadata query

Returns:

Estimate of the number of rows this relational expression will return

deriveRowType

protected RelDataType deriveRowType()

Overrides:

deriveRowType in class AbstractRelNode

computeDigest

protected java.lang.String computeDigest()

Description copied from class: AbstractRelNode

Computes the digest. Does not modify this object.

Overrides:

computeDigest in class AbstractRelNode

Returns:

Digest

replaceRel

void replaceRel(RelNode newRel)

Replaces the implementation for this expression with a new one.

Parameters:

newRel - new expression

getCurrentRel

public RelNode getCurrentRel()

Returns:

current implementation chosen for this vertex