Transaction management in an object-oriented data base system
Abstract The newer generation of data base applications requires modeling techniques more powerful than the ones offered by relational systems. Object-oriented data bases provide a promising alternative for advanced applications such as computer-aided design (CAD) and multimedia data bases (MMDB). However, many issues in object-oriented systems are still not well understood. Transaction management is one such issue. Transactions in advanced applications such as CAD and MMDB differ from those in conventional applications in many respects. Some of these differences include the duration of transactions, granularity of transaction management features, and complications arising out of various object-oriented characteristics such as class hierarchies, encapsulation, and inheritance. There is need for research in the area of transaction management in object-oriented data bases. The cooperating nature of transactions in applications such as CAD and MMDB requires the redefinition of concepts such as consistency and correctness. The notion of correctness used in conventional systems (i.e., serializability) is no longer appropriate in the object-oriented environment. In this article, we define an alternate transaction model that is more suitable for the kinds of applications arising in object-oriented data bases and develop correctness criteria for concurrent executions in such a system, taking into consideration the class and class composition hierarchies.