一种动态调整串行化顺序的实时并发控制协议  

A Real-time Concurrency Control Protocol Using Dynamical Adjustment of Serialization Order

作　　者：刘波[1] 范士明[1] 刘华[1] 

机构地区：[1]北京卫星信息工程研究所,北京100086

出　　处：《小型微型计算机系统》2013年第3期443-449,共7页Journal of Chinese Computer Systems

基　　金：总装备部预研基金项目(9140A04020309HT6401)资助

摘　　要：实时并发控制协议用来控制并发事务间的相互作用,已满足实时数据库的一致性.本文提出一种四阶段实时并发控制协议HTRCC-DASO,协议在读或等待阶段基于事务优先级动态调整串行化顺序,通过阻塞或及早重启低优先级事务,使高优先级事务率先提交并降低事务重启开销.在验证阶段检查事务读写集合的外部一致性和相互一致性并调整活动事务的时间戳间隔,确保满足事务时态一致性和调度冲突可串行化.通过引入相似性概念,提出了HTRCC-DASO的改进版本:SHTRCC-DASO,性能测试结果显示,SHTRCC-DASO协议能保证良好的实时性能.Real-time concurrency control protocol,which used to isolate the interference of concurrent transactions in real-time database,is needed to achieve consistency.A four phase′s real-time concurrency control protocol which is called HTRCC-DASO is proposed.In reading or waiting phase,the serialization order of transactions is dynamically adjusted based on their priority.High priority is allowed to commit earlier and the restart overhead of aborted transactions is reduced by blocking or restart low-priority transactions as soon as possible.In validation phase,the exterior and mutual consistency of read and write set of transaction are checked and timestamp interval of all transactions at reading or waiting phase is adjusted to satisfy the requirements of temporal consistency and conflict serializability.In order to achieve better real-time performance,an enhanced HTRCC-DASO,called SHTRCC-DASO is proposed by introducing the concept of similarity.Performance tests show that SHTRCC-DASO can ensure very well real-time performance.

关 键 词：实时数据库 实时并发控制 相似冲突可串行化 时态一致性 

分 类 号：TP311[自动化与计算机技术—计算机软件与理论]