Introduction

Abstract

Database management systems (DBMSs) have become a standard tool for manipulating large volumes of data on secondary storage. To enable fast access to stored data according to its content, organizational methods or structures known as indexes are used. While indexes are optional, as data can always be located by sequential scanning, they are the primary means of reducing the volume of data that must be fetched and examined in response to a query. In practice, large database files must be indexed to meet performance requirements. In fact, it has been noted [13] that indexes are the primary and most direct means in reducing redundant disk I/O.