Priority Heuristic in Mobile Distributed Real Time Database Using Optimistic Concurrency Control

Priority scheduling among running transactions is one of the most important issues in the design of mobile distributed real-time database systems (MDRTDBS). In MDRTDBS, to perform correct transaction scheduling, several priority heuristics with different concurrency control methods are used, so that, it could minimize transaction abort rate. Priority heuristic approaches deal with problem of assigning the priorities among transactions so that it could helpful with concurrency control (CC) mechanism to achieve typical time constraint. In recent few years, the performance of CC protocols of distributed real-time database Systems (DRTDBS) have been examined using different priority heuristics methods. However, very few numbers of approaches have been proposed on priority heuristics for wireless environments. Hence, a new priority heuristic method based on deadline computed by considering write only operations has been proposed for wireless environments. It is improved priority heuristic approach which shows better results than earlier priority heuristics. In recent years, researchers have classified the transactions in two types called as Read only transactions (ROT) and Update transaction. This new priority heuristic for mobile environment considers ROT and update transactions separately. Further, a study has also been done to examine the impact of these priority heuristics as compared with number of locks and mixed method approaches.