FEDERATED DATABASE-MANAGEMENT SYSTEM - REQUIREMENTS, ISSUES AND SOLUTIONS

The use of database management systems (DBMS) to replace conventional file processing systems has dramatically increased in the past years. Although the use of DBMSs overcomes many of the limitations of file processing systems, many important applications require access to and integration of information among several and often incompatible DBMSs. In this paper we discuss an approach, known as the federated database approach, that allows users and applications to access and manipulate data across several heterogeneous databases while maintaining their autonomy. We discuss the requirements and objectives of a federated database management system, and outline the major issues and challenges for building and using such a system. In particular, we address the design issues from three angles: transaction management, system architecture, and schema integration. Also, we present a five-step integration methodology followed by a comprehensive example to illustrate the concepts and techniques involved in this integration methodology.