The Design, Implementation, and Performance Evaluation of BERMUDA

We describe the design and implementation of BERMUDA, which is a loosely coupled system interfacing Prolog to the Britton-Lee Intelligent Database Machine (IDM-500). BERMUDA allows multiple concurrent Prolog processes, possibly running on different machines, to share a database. In addition, it preserves the semantics of Prolog programs and makes the use of the database system transparent to the user. We discuss several architectural issues faced by such systems and the approach adopted for each one in BERMUDA. We also present the performance results of a variety of experiments with the system. These include single-user benchmarks of BERMUDA against stand-alone Prolog and stand-alone IDM, detailed profiling of the costs of the modules of BERMUDA that shows the overhead imposed by the interface, and multiuser benchmarks of BERMUDA that show how the system behaves under heavier load. These experiments demonstrate the effectiveness of loosely coupled systems in general and of BERMUDA specifically. They also help in the identification of some aspects of the design and implementation of BERMUDA that could be improved. >