Database Systems

APPENDIX 2

Review of Hashing

Hashing is a technique for mapping data from a large set to limited space in a much smaller set. This appendix provides an overview of the subject. The appendix covers the fundamentals of hashing under the following captions:

• Introduction
• Hash Functions
• Collision Resolution
• Hashing in Java
• Summary and Concluding Remarks

A2.1 Introduction

In computer science, it is always important to establish mapping functions between (what is called) the conceptual user view of data and actual physical storage reality in the computer system. The former is what the end-user sees; the latter is what is actually stored on the storage ...