一种新的混合实时事务并发控制算法

单一的实时事务并发控制策略因为对事务性能以及事务对数据的访问方式有着特殊限制而无法满足不同类型事务同时并存的混合实时数据库的要求.针对不同类型实时事务特征,提出了一种新的混合实时事务并发控制算法,对不同类型实时事务采用不同并发控制策略,具有极强的针对性和自适应性,算法同时通过分析数据的相关语义,利用数据相似性定义,合理放宽可串行化的正确性标准,在优先考虑硬实时事务的前提下,尽可能增加软实时事务成功提交的比例以提高系统整体性能.仿真实验结果证明MRTT_CC算法性能良好.

New real-time mixed transaction concurrency control protocol

Due to the very different perform requirements and data access restrictions of each type of real-time transactions, concurrency control protocols which is designed for the systems with a single type of real-time transactions may not be suitable to mixed real-time database systems, where various types of real-time transactions coexist in the systems concurrently. The new MRTT_CC algorithm adopts different concurrency control strategies to resolve conflicts between different types of real-time transactions. Serializable correctness standard is relaxed reasonably by exploring data semantics and data similarity definition thus to guarantee the performance of hard real-time transactions and reduce the number of deadlines missed of the soft real-time transactions. Simulation experiments show that the new algorithm has gained good performance.