Database Programming and Design; Freeman pubs, Sept. 1998.
Source Material (htm).As information systems become larger more functions can be assigned to middleware, avoiding problems associated with fat clients as well as with fat servers. We describe mediators, modules which occupy an intermediate layer. They perform functions as integrating domain-specific data from multiple sources, reducing data to an appropriate level, and restructuring the results into object-oriented structures. Their output is formulated for effective use by the clients. A major benefit of mediation is the scalability and long-term maintenance of the integrated information systems structure, due to the decoupling of servers and clients. Examples of current applications illustrate the technology and its effectiveness.
Crucial concepts are: Value-added middleware services are domain-specific, providing a natural partitioning, which in turn enhances scalability and maintainability.