Abstract

Due to its potential for a high degree of parallelism, optimistic concurrency control is expected to perform better than two-phase locking when integrated with priority-driven CPU scheduling in real-time database sys-tems. In this paper, we examine the overall effects and the impact of the overheads in-volved in implementing real-time optimistic concurrency control. Using a locking mecha-nism to ensure the correctness of the imple-mentation, we develop a set of optimistic con-currency control protocols and evaluate them on a testbed. Throu h experiments, we in-vestigate, in depth, t R e effect of the locking mechanism on the performance of optimistic concurrency control protocols, and we com-pare the locking-based optimistic approach with a class of two-phase locking protocols. The experimental results indicate that the physical implementation schemes have a sig-nificant impact on the performance of real-time optimistic concurrency control. 1

Citations