Concurrency control in real - time broadcast environments q

Owing to the unique characteristics of real-time broadcast environments, serializability is too strong as a correctness criterion and not suitable for mobile real-time transactions. Considering that relaxing serializability such as epsilon and similarity serializability may sacrifice database consistency to some extent, we propose using a correctness criterion called weak serializability. In this paper, we formally define weak serializability at first. After the necessary and sufficient conditions for weak serializability are shown, corresponding concurrency control protocol based on this criterion is outlined for real-time broadcast environments. Finally, in a series of simulation studies, experimental results show that the proposed protocol helps more mobile real-time transactions to meet their deadlines and improves response time while database consistency is maintained. 2002 Elsevier Inc. All rights reserved.