开放式环境下支持协作设计的并发控制机制的研究

Study on concurrency control mechanism supporting cooperative design under open environment

针对现有的分布式并发控制机制存在的缺陷,提出一种适合开放式环境下协作设计事务的并发控制机制。该机制将只读事务和更新事务区分开来,只读事务在执行时遵守多版本时间戳排序协议,而更新事务的执行将按基于两阶段有序相容性封锁的多粒度封锁协议进行。这样不仅使用户可以快速得到查询结果,而且有效提高了协作设计事务的并发度。实验分析表明,该机制比较适合于开放式的协同设计环境。

Based on the analysis of the disadvantages of the present distributed concurrency control protocol, a concurrency control protocol for cooperative design transaction in open environment was proposed. Under the new protocol, read-only transaction and update transaction was distinguished. The former abided the multiversion timestamp ordering protocol, while that of the latter followed the multi-granularity locking mechanism based on ordered sharing locks.The new protocol not only made user＇s query quickly, but also enhanced concurrency of cooperative transaction effectively. The experiment shows that the new protocol is fit for the open environment that supports cooperative design.