ca.uqac.dim.turtledb

Class BinaryRelation

java.lang.Object

ca.uqac.dim.turtledb.Relation

ca.uqac.dim.turtledb.BinaryRelation

Direct Known Subclasses:

Join

public abstract class BinaryRelation
extends Relation

A binary relation has exactly two operands.

Author:

sylvain

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	BinaryRelation.BinaryRelationCacheIterator
protected class	BinaryRelation.BinaryRelationStreamIterator

Field Summary

Fields

Modifier and Type	Field and Description
protected Relation	m_left
protected Relation	m_right

Fields inherited from class ca.uqac.dim.turtledb.Relation

m_streamingMode

Constructor Summary

Constructors

Constructor and Description
BinaryRelation()

Method Summary

Modifier and Type	Method and Description
protected void	acceptBinary(QueryVisitor v)
Relation	getLeft()
Relation	getRight()
void	setLeft(Relation r)
void	setRight(Relation r)
int	tupleCount() Returns the number of actual tuples present in the query.

Methods inherited from class ca.uqac.dim.turtledb.Relation

accept, cacheIterator, contains, getCardinality, getDegree, getSchema, isFragment, isLeaf, iterator, setStreamingMode, streamIterator, toString

Methods inherited from class java.lang.Object

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

Field Detail

m_left

protected Relation m_left

m_right

protected Relation m_right

Constructor Detail

BinaryRelation

public BinaryRelation()

Method Detail

setLeft

public void setLeft(Relation r)

setRight

public void setRight(Relation r)

getLeft

public Relation getLeft()

getRight

public Relation getRight()

acceptBinary

protected void acceptBinary(QueryVisitor v)
                     throws QueryVisitor.VisitorException

Throws:

QueryVisitor.VisitorException

tupleCount

public int tupleCount()

Description copied from class: Relation

Returns the number of actual tuples present in the query. This number is different from the cardinality of the query; it counts the number of tuples that are present in the leaves of the query tree.

Specified by:

tupleCount in class Relation

Returns:

The tuple count