【摘要】 在实时主动数据库中,事务不仅有时间约束,而且事务执行可能触发其它事务执行。传统并发控制协议不适应于实时主动数据库系统。该文研究了实时主动数据库事务执行模式,提出了有效性检查并发控制协议。协议使用动态调整串行次序策略,避免不必要的事务重启动。通过仿真模拟与HP2PL协议和OCC-TI-WAIT-50协议进行了比较。结果表明,该协议能有效地降低事务延误截止时间率和事务重启动率,性能优于HP2PL和OCC-TI-WAIT-50协议。更多还原

【Abstract】 In real-time active database systems (RTADBSs),transactions not only have timing constraint ,but also trigger other transactions.The conventional concurrency control protocols are not suitable for RTADBSs.This paper studies the model of transaction execution and presents real-time validation concurrency control protocol(RTVCC)for RTADBSs.The protocol uses dynamic adjustment of serialization in order to avoid unnecessary transactions restarts.The protocol presented is compared with HP2PL protocol and OCC-TI-WAIT-50protocol by simulation.The experiments show that the protocol can effectively reduce miss rate and restart rate of transactions.It performs better than HP2PL protocol and OCC-TI-WAIT-50protocol under normal load.更多还原