The Implement Technology For Data Manipulation Of Mobile Real-Time Database Management System

With the increasingly higher efficiency requirements by real-time application,the fast development of mobile communication technology,and the vast popularity of mobile computers,Mobile Real-Time Database System(MRTDBS),which integrate the mobile computation,real-time application and traditional database technology,has become a latest research topic in database area.Data manipulation is one of the key technology for the system,and data manipulation subsystem is one of the important portion.It aims to realize the operations of data insert.delete,query and update.Compared with the traditional database management system,Mobile Real-Time Database Management System has the characteristics of real time,mobility and frequent disconnection.So there are some differents in the implement technology for data manipulation between them.With respect to the valid data in mobile real-time database management system,an algorithm about select,project and join algebraic computation based on T-tree is researched in this paper.Through handling the valid data,the algorithm lowers the unnecessary computation on this kind of data during data manipulation process,improves the efficiency on real-time data manipulation,and ensures data availably during real-time transaction's satisfying its deadline and its successful submission.With respect to the mobility and the frequent disconnection of networks,an asynchronous data manipulation strategy is researched in this paper.In this mobile computing environment,customers can obtain required data from the copy of the data kept by the mobile client,enable data manipulation,and return a result of partly correct but timely to customers.This strategy satisfies the requirements of real-time operating the database.Based on the research on the implement technology for data manipulation of this system,the data manipulation module for real-time database management system is designed.Through simulation,the correct of this algorithm is verified.Finally,experiment results show that the algorithm and the strategy reduce executive time,and obtain better performance.