Using importance of transactions and optimistic concurrency control in firm real-time databases

In a real-time database system, it is difficult to meet all of the timing constraints due to the consistency requirements of the underlying database. However, when the transactions in the system are heterogeneous, they are not all of the same importance-some are of greater importance than others. In this paper, we propose a new protocol called OCC-PDATI (Optimistic Concurrency Control Protocol using Dynamic Adjustment of serialization order and Transaction Importance), which uses information about the importance of the transactions in the conflict resolution. Performance studies of our protocol have been carried out in a prototype real-time database system. The results clearly indicate that OCC-PDATI meets the goal of favoring transactions of high importance.