在移动实时数据库系统中,事务的关键性代表实时事务的时间紧迫性,由于实时事务的紧迫程度不同,为了保证事务的时间正确性,因而有必要区分事务的关键性提出相应的并发控制策略。该文按满足截止时间的重要性将实时事务分为软、硬事务加以研究,在此基础上分别提出了三种区分事务关键性的优先级并发控制策略,对三种优先级策略进行了性能比较并提出了改进方法。研究结果表明,将实时事务按关键性分类有利于设计事务优先级分派及调度策略。
In mobile real-time database system,the criticality in real-time transaction is on behalf of the urgency of the time.Due to the urgency of realtime transaction in varying degrees,in order to ensure the time accuracy of the transaction,it is necessary to distinguish criticality of transaction and propose corresponding concurrency control strategy.tuY the real-time transaction which is divided into software and hardware transaction by the importance of meeting the deadline.Based on this,propose three priority concurrency control strategies to distinguish the criticality of transaction, compare the performance of three strategies and propose improved method. The results show that classifying real - time transaction is in favor of the designing strategy in transaction priority assignment and scheduling.