An Improved, Prioritized Concurrency Control Scheme with Performance Gain in Mobile Environments

In a mobile computing environment, clients can access shared data irrespective of their physical location and can be updated by each client independently. This leads to inconsistency of the data. Several concurrency control techniques are proposed in literature to prevent data inconsistency. In this paper we first analyze the existing scheme of concurrency control without locking and justify its performance limitations. A new priority based scheme is proposed in which priority is given to the older transaction whenever conflict arises, there by decreasing transaction re-executions and current load of the database server. Experimental results show performance benefits such as increase in commit rate and decrease in reexecution of the transactions. K eywordsAbsolute Validity Interval, Priority Value, Semaphore, Mobile Host, Fixed Host