BUILDING A FEDERATED RELATIONAL DATABASE SYSTEM - AN APPROACH USING AKNOWLEDGE-BASED SYSTEM

Due to the emerging interest in integrating different application envi ronments, there have been many recent proposals for federated systems. In this paper, a federated system that permits the integration of het erogeneous relational databases using a terminological knowledge repre sentation system is presented. In particular, two of the system's comp onents: the translator and the integrator are explained in depth. The translator permits one to obtain a terminology from a relational schem a, either semiautomatically, by expressing database properties, or man ually, by using a set of predefined operations. In turn, the integrato r generates a federated terminology by integrating several terminologi es using the semantics expressed as correspondences between the data e lements of different terminologies. Unlike many other approaches, the use of a terminological system permits us to obtain a semantically ric her federated terminology and, at the same time, define a wider and mo re consistent integration process.