Synchronization of nested transactions in multidatabase systems

Abstract

In recent years, the dramatic growth of electronic commerce has been made by the proliferation of the Internet and the development of communication technologies. Electronic commerce involves the management of business process that support critical business functions, such as issuing purchase order, inventory control and payment transactions, etc. Especially, today````s electronic business processes involve more than one business partner and the processing work flows are very sophisticated. It will be more desirable to support nested transactions for the transaction processing in sophisticated, ad-hoc work flow applications. The simple control structure of flat global transactions is not sufficient to support sophisticated applications in multidatabase systems. To support sophisticated applications effectively, it is desirable to provide nested transactions. For ensuring consistency of databases against concurrently running nested transactions, a concurrency control scheme is required. Lock inheritance mechanisms that have been proposed to synchronize nested transactions in non-autonomous distributed environments can not be applied to the nested transaction management in multidatabase systems because they can not be working without sacrificing local autonomy. In this thesis, we propose a new concurrency control scheme for nested transactions in multidatabase systems. Our concurrency control scheme is designed to preserve local autonomy. We introduce two types of serializability as the sufficient correctness criteria for the concurrent execution of nested transactions: intra-transaction serializability and inter-transaction serializability. It is shown that our concurrency control scheme guarantees serializability by proving that our scheme satisfies both types of serializability. Our concurrency control scheme works in one of the important classes of MDBSs, in which all LDBSs employ strict two-phase locking. We, also, deal with deadlocks that may occur in our...