Logic-based approach for realizing a federated information system

The formalism, tools and techniques used for creating and maintaining federated information systems (FISs) need to be chosen carefully. The authors propose a logic based approach to the realization of a federated information system. They argue that the logic based approach is beneficial in several ways. It enables one to address the schema/view integration problem formally in contrast to most of the earlier work. First-order languages are rich enough to be used for the canonical representation (if not as the user interface) at the intermediate level. Unlike a conventional DBMS, a logic-based system (e.g. KB-Prolog) can compensate for operations that lack in the underlying systems (e.g. outer-join, recursive queries) without additional implementation effort. Also, the full power of rules will be available for expressing meta-information both declaratively and procedurally in one language. This has the added advantage of providing extensibility. Finally, the techniques developed can be rapidly prototyped and tested before migrating them to real systems