vishnu.model.algebra
Class Projection

java.lang.Object
  vishnu.model.algebra.AbstractUnaryRelation
      vishnu.model.algebra.Projection

All Implemented Interfaces:

java.lang.Cloneable, Relation, UnaryRelation

public class Projection
extends AbstractUnaryRelation

Esta clase modela la relacion de proyeccion del algebra relacional.

Author:

Mariano Tepper

Field Summary

Fields inherited from class vishnu.model.algebra.AbstractUnaryRelation

algorithm

Constructor Summary

Projection(Relation p, java.util.List<java.lang.String> columns)

Method Summary

java.lang.Object	clone() Clona la relacion.
java.util.List<java.lang.String>	columnNames()
void	columnNames(java.util.List<java.lang.String> columnNames)
boolean	equals(java.lang.Object o)
protected TableSignature	getRestrictedSignature()
boolean	hasChanged() Indica si se realizaro alguna modifiaccion en la relacion.
java.lang.String	toString()

Methods inherited from class vishnu.model.algebra.AbstractUnaryRelation

algorithm, algorithm, perform, relation, relation, setChanged, setContext, signature

Methods inherited from class java.lang.Object

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

Constructor Detail

Projection

public Projection(Relation p,
                  java.util.List<java.lang.String> columns)

Method Detail

columnNames

public java.util.List<java.lang.String> columnNames()

getRestrictedSignature

protected TableSignature getRestrictedSignature()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

clone

public java.lang.Object clone()

Description copied from interface: UnaryRelation

Clona la relacion.

Specified by:

clone in interface UnaryRelation

Specified by:

clone in class AbstractUnaryRelation

hasChanged

public boolean hasChanged()

Description copied from interface: Relation

Indica si se realizaro alguna modifiaccion en la relacion.

Specified by:

hasChanged in interface Relation

Overrides:

hasChanged in class AbstractUnaryRelation

Returns:

true si se realizaron cambios, false si no.

columnNames

public void columnNames(java.util.List<java.lang.String> columnNames)

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object