com.bigdata.htree

Class HTreeVersusHashMapDemo

java.lang.Object

com.bigdata.htree.HTreeVersusHashMapDemo

public class HTreeVersusHashMapDemo
extends Object

A simple demonstration which may be used to compare the HTree performance against a Java collections class such as HashMap or LinkedHashMap. This demonstration is focused on the performance curve when inserting a large number of keys into a collection. The Java collection classes are faster for small numbers of keys, but the HTree rapidly out performs them as the #of keys grows larger.

The HTree is run against the MemoryManager. This means that the data for the HTree is mostly stored on the Java native process heap using ByteBuffer.allocateDirect(int). Thus even a very large HTree instance can be run with a very small JVM object heap and creates nearly no GC pressure.

The HTree permits multiple entries for the same key. While variable length keys are supported, the key for the HTree is typically a 32 (or 64) bit hash code for the value stored in the HTree. Normally, the application will lookup all tuples having the same hash code and then enforce Set or Map semantics by scanning those tuples for the presence of the same application object.

Version:

$Id$

Author:

Bryan Thompson, Martyn Cutcher

Constructor Summary

Constructors

Constructor and Description
HTreeVersusHashMapDemo()

Method Summary

Methods

Modifier and Type	Method and Description
static void	main(String[] args)

Methods inherited from class java.lang.Object

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

Constructor Detail

HTreeVersusHashMapDemo

public HTreeVersusHashMapDemo()

Method Detail

main

public static void main(String[] args)

Parameters:

args -