一种基于强可有序化标准的长事务调度算法

A Scheduling Algorithm for Long Duration Transaction Based on Strong Orderability Criterion

现有的长事务并发机制在解决并发冲突和回滚时往往需要依赖于人工干预,且故障恢复的代价较高.提出了一种面向长事务的调度正确性标准——强可有序化标准,并提出了基于该标准的长事务调度算法.该算法利用事务的语义知识以提高事务的并发效率,同时使得长事务的恢复机制大为简化,且回滚代价大大降低.实验结果表明该算法对长事务具有较好的并发处理效果和恢复效率.

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.