【摘要】 在移动数据库系统中 ,计算平台的移动性、频繁的断接性以及长事务等特性使得传统的事务处理模式不再适用 .为了解决移动数据库中的事务处理问题 ,提出了一种新的移动事务处理模型——乐观两阶段提交移动事务模型 ( O2 PC-MT) .该模型采用乐观并发控制与两阶段提交协议相结合的方法 ,对移动事务的长事务特性提供了灵活与有效的支持 ;此外 ,该模型允许移动计算机分多次发送事务操作 ,且在事务执行的过程中可以任意移动 ,从而提供了对交互式事务及随意移动性的支持 .实验结果表明 ,与基于两段锁协议及其变形的其它移动事务处理模型相比 ,O2 PC-MT提高了系统的事务吞吐率并改善了系统的总体性能更多还原

【Abstract】 In mobile database systems, new features such as mobility, disconnection and long-lived transactions make traditional transaction processing schemes no longer suited. To solve this problem, a new mobile transaction model, O2PC-MT, is proposed in this paper. The O2PC-MT combines optimistic concurrency control with two-phase locking in mobile transaction processing, and utilizes two-phase commit protocol for the global commitment of mobile transactions. In this way, the O2PC-MT provides an effective support for the long-lived transaction property. In addition, mobile computers are allowed to submit mobile transactions in multiple request messages and to move arbitrarily during transaction execution. Therefore, the O2PC-MT provides a flexible support for interactivity and arbitrary mobility. The experiment results show that the O2PC-MT model outperforms the previously proposed mobile transaction models that utilize the two-phase locking or its variants for mobile transaction processing.更多还原