Integration of information systems using an object-oriented approach

With ever-increasing amounts of information being stored on computers, there is a growing demand for systems that will support convenient access to information that is distributed over multiple information systems. In this paper we describe a system called KOPERNIK*, which uses an object-oriented approach to define partly integrated views of a collection of autonomous information bases. These views, as well as multi-information-base queries, are described using a language-independent meta-model. We provide a classification of incompatibilities between autonomous information systems, in order to define multi-information-base classes and messages and the subclass I superclass hierarchy. KOPERNIK * uses the meta-model to simplify the decomposition of queries into subqueries for individual information systems. We illustrate the processing of subqueries by relational systems and by information retrieval systems