An autonomous decentralized 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 for this objective is realized in an autonomous decentralized 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 resolve heterogeneity in data models and database systems at local sites. At relational viewports, both relational and object-oriented schemas defined at other sites are translated via scripts and viewed as relational schemas. Similarly at object-oriented viewports, any schema defined at other sites is viewed as object-oriented. Views are used to resolve semantic heterogeneity within viewports. The paper describes a stepwise approach to resolving the three types of heterogeneity and its implementation using active objects