Abstract:
Existing concurrency control mechanisms for long duration transactions need human's participation when solving concurrent conflicts or performing rollback, and the cost for rolling back a long duration transaction is high. In this paper, a new correctness criterion—The strong orderability criterion for the concurrency control of long duration transactions is defined, and a scheduling algorithm based on the criterion is proposed. The algorithm makes use of the semantic knowledge of transactions to provide a higher degree of concurrency for long duration transactions. At the same time, the recovery mechanism of long duration transactions is greatly simplified, and the cost for rollback is decreased. Simulation results show that the algorithm has sound concurrency management ability and recovery efficiency.