Active database rules in distributed database systems - A dynamic approach to solving structural and semantic conflicts in distributed database systems

While networking technology provides physical connectivity for the heterogeneous and distributed databases, the logical connectivity of such databases can be accomplished only when the heterogenetites of the objects stored in these diverse databases are resolved. However, this is still yet a major challenge that remains to be realized. In this paper, we develop a reactive multidatabase architecture that emphasizes the dynamic interactions between the local and global systems to maintain object consistency between local databases and object relativism between local and global systems so as to support the interoperability of the heterogeneous databases over time. In particular, we incorporate the Event-Condition-Action (E-C-A) rules into the architecture to provide a suitable platform for specification of global reactions to the anticipated changes of the local databases, as well as of the global users. Such rules extend the power of multidatabase systems to deal with observation of the objects and events and thus allow the explicit specification, recognition and resolution of the temporal conditions and changes. Our targeted application domains include geographic information system (GIS), scientific database system and digital libraries.