An Appropriate Semantics for Distributed Active Object-Oriented Databases on the Basis of C O-NETS Approach

The purpose of this paper is to present first results towards an appropriate approach for formally specifying in a uniform and simple way all aspects characterizing distributed active object-oriented databases (AOODB). Referred to as CO-NETS, the approach is based on a complete and a formal integration of OO concepts and constructions into a an appropriate variety of algebraic Petri nets. The CO-NETS semantics is expressed in rewriting logic with a full exhibition of a true intraas well as inter-object concurrency. The suitability of the approach for modeling AOODB may be highlighted as follows. First, it straightforwardly captures different forms of inheritance, object composition and aggregation leading to (a hierarchy of) complex classes we named components. Second, for constructing more complex OODB as interacting components via explicit interfaces, we propose an inter-component interaction pattern. Third, for querying and viewing the resulting CO-NETS database, first ideas towards an appropriate query-pattern are forwarded. Fourth, for composing business rules, we propose an appropriate event algebras which may be regarded as suitable extension of the commonly used ECA rules. Last but least, time constraints are captured by associating time-stamps with time-dependent events and transitions. keywords: distributed active OO databases, CO-NETS, rewriting logic, specification / validation phase. In Proc. of the 1st. International Conference on Software Engineering Applied to Networking and Parallel / Distributed Computing (SNPD ’00) , Fouchel, H. and Roger Y.L. (eds.),International Association for Computer and Information Science (ACIS), Reims, France, pp. 541-548, 2000 This work is supported by a DAAD schlorship.