THE DESIGN AND IMPLEMENTATION OF AN INTEROPERABLE DATABASE SYSTEM BASED ON SCRIPTS AND ACTIVE OBJECTS

Our objective is to resolve three types of heterogeneity - data model, database system, and semantic - in heterogeneous databases. The basic framework which we propose for this objective is realized in an autonomous decentralized database system (i.e., an interoperable database system), called Jasmine/M. Users describe their relational or object-oriented data models and schemas locally using the model primitives which Jasmine/M provides as a scripting language. Description using such primitives or scripts constitutes viewports, which have a role to resolve heterogeneity in data models and database systems at local sites. At relational viewports, both relational and abject-oriented schemas defined at other sites are translated via scripts and are viewed as relational schemas. Similarly at object-oriented viewports, any schema defined at other sites is viewed as object-oriented schemas. Relational and object-oriented views are used to resolve semantic heterogeneity within viewports. This paper describes a step wise approach to resolving the three types of heterogeneity, using scripts, viewports, and views, and its implementation using active objects.