gr.uoa.di.madgik.searchlibrary.operatorlibrary.join

Class HashJoin

java.lang.Object

gr.uoa.di.madgik.searchlibrary.operatorlibrary.join.HashJoin

public class HashJoin
extends Object

Class used to hold the hashtable for the hash join algorithm

Author:

UoA

Constructor Summary

Constructors

Constructor and Description
HashJoin() Creates a new HashJoin

Method Summary

Methods

Modifier and Type	Method and Description
void	add(JoinElement elem) Adds the provided element in the hashtable
boolean	isEmpty() Checks if the hashtable is empty
JoinElement	lookup(JoinElement elem) Checks if the provided element exists in the hashtable

Methods inherited from class java.lang.Object

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

Constructor Detail

HashJoin

public HashJoin()

Creates a new HashJoin

Method Detail

lookup

public JoinElement lookup(JoinElement elem)

Checks if the provided element exists in the hashtable

Parameters:

elem - The element to lookup

Returns:

The element that is stored in the hashtable if it exists, null otherwise

add

public void add(JoinElement elem)

Adds the provided element in the hashtable

Parameters:

elem - The element to add

isEmpty

public boolean isEmpty()

Checks if the hashtable is empty

Returns:

true if it is, false otherwise