Although many efficient concurrency control protocols have been proposed for real-time database systems, they are mainly designed for the systems with a single type of real-time transactions. Their performance objective is usually to minimize the number of deadline missing of soft real-time transactions or to guarantee the deadline satisfaction of hard real-time transactions. Due to the very different performance requirements of hard and soft real-time transactions, existing realtime concurrency control protocols may not be suitable to Mixed Real-time Database Systems (MRTDBS), where different types of real-time transactions, and even non-real-time transactions, may co-exist in the systems. In this paper, we propose strategies for resolving data conflicts between different types of transactions in a MRTDBS so that the performance requirements of each individual transaction type can be satisfied and, at the same time, the overall system performance can be improved. The performance of t...
Kam-yiu Lam, Tei-Wei Kuo, Tony S. H. Lee