Transaction management in object-oriented data base systems

Object-oriented data bases are fast gaining in popularity, especially with the advent of advanced applications like computer aided design (CAD) and multimedia data bases (MMDB). The modeling techniques required by these applications cannot be met by conventional data base systems. The semantic richness of the object-oriented model facilitates the modeling of advanced data base applications. These applications are characterized by long-duration cooperating transactions. Unlike the conventional data bases, serializability can no linger be the correctness criterion for concurrent transaction execution. A new transaction model for object-oriented data bases is needed. This dissertation describes our research in the area of transaction management for object-oriented data bases. A new transaction model for object-oriented data bases is defined. This model takes into consideration the unique requirements of the advanced applications. Data base consistency is now defined in terms of correctability. Object-oriented Correct Schedules (OOCS) and Object-oriented Correctable Schedules (OOCLS) are defined. This dissertation also describes a new concurrency control protocol that satisfies the correctness criterion for concurrent execution of transactions in an object-oriented data base environment, i.e. it allows only Object-oriented Correctable Schedules. Users of a data base interact with it through means of queries. Queries are then translated into transactions. The data base functionality necessary to support queries is also discussed in this research work