Extensions to optimistic concurrency control with time intervals

Although an optimistic approach has been shown to be better suited than locking protocols for real-time database systems (RTDBS), it has the problems of unnecessary restarts and heavy restart overhead. In this paper we identify the unnecessary restart problem in OCC-TI (Optimistic Concurrency Control with Time Intervals), propose a solution to this problem and demonstrate that the solution will produce a correct result. Additionally, two extensions to the basic dynamic adjustment of the serialization order conflict resolution method used in OCC-TI are proposed. Experiments with a prototype implementation of a real-time database system show that the proposed method clearly outperforms the original OCC-TI.