Using Importance of Transactions and Optimistic Concurrency Control in Firm Realtime Databases

In a real-time database system, it is difficult to meet all tim-ing constraints due to the consistency requirements of the underlying database. However, when the transactions in the system are heterogeneous, they are not of the same impor-tance- some are of greater importance than others. In this paper, we propose a new optimistic concurrency control pro-tocol called OCC-PDATI which uses information about the importance of the transactions in the conflict resolution. Per-formance studies of our protocol have been carried out in the prototype real-time database system. The results clearly indicate that OCC-PDATI meets the goal of favoring trans-actions of high importance.