Stable transaction management for preserving the global integrity constraints in multidatabase systems

Multidatabase systems (MDBSs) are an integration of local database systems into a global distributed database system. The objectives of global transaction management are to avoid inconsistent retrieval and to guarantee the global serializability under the existence of indirect conflict which is unknown to the global transaction manager (GTM). Research has shown that it is difficult to design the global concurrency control method because of local autonomy. Hence, we adopt the characteristics of global integrity constraints so that inconsistent global schedules can be prohibited and the higher degree of concurrency can be achieved. We propose the transaction model for maintaining the global integrity constraints and define the stable global transaction that cannot have any indirect conflict between global transactions. We also propose the optimistic concurrency control method to guarantee the global serializability and logical consistency.