The federated database management system: an architecture of distributed systems for the 90´s

Many important applications require integration of information among several, often incompatible, database management systems. The authors discuss an approach, known as the federated database approach, that allows users and applications to access data across several heterogeneous databases while maintaining their autonomy. The authors discuss the requirements and objectives of federated database management system and outline the major issues and challenges for building and using such a system. In particular, they address the design issues from three angles: transaction processing, system architecture, and schema integration. Also, a five-step integration methodology, followed by a comprehensive example to illustrate the concepts and techniques involved in this integration methodology, is presented