Object Oriented Approach for Integration of Heterogeneous Databases in a Multidatabase System and Local Schemas Modifications Propagation

One of the challenging problems in the multidatabase systems is to find the most viable solution to the problem of interoperability of distributed heterogeneous autonomous local component databases. This has resulted in the creation of a global schema over set of these local component database schemas to provide a uniform representation of local schemas. The aim of this paper is to use object-oriented approach to integrate schemas of distributed heterogeneous autonomous local component database schemas into a global schema. The resulting global schema provides a uniform interface and high level of location transparency for retrieval of data from the local component databases. A set of integration operators are defined to integrate local schemas based on the semantic relevance of their classes and to provide a model independent representation of virtual classes of the global schema. The schematic representation and heterogeneity is also taken into account in the integration process. Justifications about Object-Oriented Modal are also discussed. Bottom up local schema modifications propagation in Global schema is also considered to maintain Global schema as local schemas are autonomous and evolve over time. An example illustrates the applicability of the integration operator defined. KeywordsMultidatabase, Object-Oriented Database, Heterogeneous Databases, Distributed Databases, Schema Integration, Schema Evolution, Schema Transformation, Correspondence Assertions, Schema Mapping.