vishnu.model.algebra
Class EquiJoin

java.lang.Object
  vishnu.model.algebra.AbstractBinaryRelation
      vishnu.model.algebra.EquiJoin

All Implemented Interfaces:

BinaryRelation, Join, Relation

public class EquiJoin
extends AbstractBinaryRelation
implements Join

Un EquiJoin es un join cuya condicion contiene, en su condicion de restriccion, al menos una igualdad entre una columna de r y una columna de s y el primer nivel de relaciones es de ANDs, es decir, el join es de la forma: (s Join[s.a==r.b AND (*) ] r) TODO revisar que se cumpla la condicion de EquiJoin (hard! ver JoinTranslationStage)

Author:

Mariano Tepper y Hernan Rancati

Nested Class Summary

Nested classes/interfaces inherited from interface vishnu.model.algebra.Relation

Relation.Context, Relation.ContextNotSelectedException

Field Summary

Fields inherited from class vishnu.model.algebra.AbstractBinaryRelation

r, s

Constructor Summary

EquiJoin(Relation r, Relation s, SQLConditionalExpression e)
Creates a new instance of join

Method Summary

SQLConditionalExpression	conditions()
boolean	equals(java.lang.Object o)
int	hashCode()
java.lang.String	toString()

Methods inherited from class vishnu.model.algebra.AbstractBinaryRelation

algorithm, algorithm, debugging, hasChanged, leftRelation, leftRelation, perform, rightRelation, rightRelation, setChanged, setContext, signature

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface vishnu.model.algebra.BinaryRelation

leftRelation, leftRelation, rightRelation, rightRelation

Methods inherited from interface vishnu.model.algebra.Relation

algorithm, algorithm, hasChanged, perform, setChanged, setContext, signature

Constructor Detail

EquiJoin

public EquiJoin(Relation r,
                Relation s,
                SQLConditionalExpression e)

Creates a new instance of join

Method Detail

toString

public java.lang.String toString()

Specified by:

toString in interface Join

Overrides:

toString in class java.lang.Object

conditions

public SQLConditionalExpression conditions()

Specified by:

conditions in interface Join

equals

public boolean equals(java.lang.Object o)

Specified by:

equals in interface Join

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Specified by:

hashCode in interface Join

Overrides:

hashCode in class java.lang.Object