org.eigenbase.rel
Class SetOpRel

java.lang.Object
  org.eigenbase.rel.AbstractRelNode
      org.eigenbase.rel.SetOpRel

All Implemented Interfaces:

Cloneable, RelNode

Direct Known Subclasses:

IntersectRel, MinusRel, UnionRelBase

public abstract class SetOpRel
extends AbstractRelNode

SetOpRel is an abstract base for relational set operators such as union, minus, and intersect.

Version:

$Id: //open/dev/farrago/src/org/eigenbase/rel/SetOpRel.java#9 $

Author:

John V. Sichi

Field Summary

protected boolean	all
protected RelNode[]	inputs

Fields inherited from class org.eigenbase.rel.AbstractRelNode

digest, id, nextId, rowType, traits

Fields inherited from interface org.eigenbase.rel.RelNode

emptyArray

Constructor Summary

protected

SetOpRel(RelOptCluster cluster, RelTraitSet traits, RelNode[] inputs, boolean all)

Method Summary

abstract SetOpRel	clone(RelNode[] inputs, boolean all)
protected RelDataType	deriveRowType()
void	explain(RelOptPlanWriter pw)
RelNode[]	getInputs() Returns an array of this relational expression's inputs.
boolean	isDistinct() Returns whether the same value will not come out twice.
boolean	isHomogeneous() Returns whether all the inputs of this set operator have the same row type as its output row.
boolean	isHomogeneous(boolean compareNames) Returns whether all the inputs of this set operator have the same row type as its output row.
void	replaceInput(int ordinalInParent, RelNode p) Replaces the ordinalInParentth input.

Methods inherited from class org.eigenbase.rel.AbstractRelNode

childrenAccept, clone, cloneTraits, collectVariablesSet, collectVariablesUsed, computeDigest, computeSelfCost, getChildExps, getCluster, getCollationList, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getOrCreateCorrelVariable, getQuery, getRelTypeName, getRows, getRowType, getTable, getTraits, getVariablesStopped, inheritTraitsFrom, isAccessTo, isValid, onRegister, recomputeDigest, register, registerCorrelVariable, setCorrelVariable, toString

Methods inherited from class java.lang.Object

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

Field Detail

inputs

protected RelNode[] inputs

all

protected boolean all

Constructor Detail

SetOpRel

protected SetOpRel(RelOptCluster cluster,
                   RelTraitSet traits,
                   RelNode[] inputs,
                   boolean all)

Method Detail

clone

public abstract SetOpRel clone(RelNode[] inputs,
                               boolean all)

isDistinct

public boolean isDistinct()

Description copied from interface: RelNode

Returns whether the same value will not come out twice. Default value is false, derived classes should override.

Specified by:

isDistinct in interface RelNode

Overrides:

isDistinct in class AbstractRelNode

getInputs

public RelNode[] getInputs()

Description copied from interface: RelNode

Returns an array of this relational expression's inputs. If there are no inputs, returns an empty array, not null.

Specified by:

getInputs in interface RelNode

Overrides:

getInputs in class AbstractRelNode

explain

public void explain(RelOptPlanWriter pw)

Specified by:

explain in interface RelNode

Overrides:

explain in class AbstractRelNode

replaceInput

public void replaceInput(int ordinalInParent,
                         RelNode p)

Description copied from interface: RelNode

Replaces the ordinalInParent^th input. You must override this method if you override RelNode.getInputs().

Specified by:

replaceInput in interface RelNode

Overrides:

replaceInput in class AbstractRelNode

deriveRowType

protected RelDataType deriveRowType()

Overrides:

deriveRowType in class AbstractRelNode

isHomogeneous

public boolean isHomogeneous(boolean compareNames)

Returns whether all the inputs of this set operator have the same row type as its output row.

Parameters:

compareNames - whether or not column names are important in the homogeneity comparison

isHomogeneous

public boolean isHomogeneous()

Returns whether all the inputs of this set operator have the same row type as its output row. Equivalent to isHomogeneous(true).