A Strategy Of Buffer Management Embedded Mobile Real-time Database Management System

With the fast development of mobile communication technology and the large number of popular mobile computation, Embedded Mobile Real-time Database System which integrate the mobile computation, real-time application and traditional database technology become a focus in the research of database. The buffer management in this system is in a special basic position, which should consider about the limitation of resource, time and application of environmental just like dispatch and control strategy ,then design a efficient buffer management algorithm which support the real-time and movement of the transaction.Traditional buffer management algorithms are from the operating system management pages algorithms such as LRU, FIFO,CLOCK etc, although the realization of these algorithms are simple but they are not suitable for real-time mobile environment; another research direction is more buffer pools configuration and the realization of the algorithm is difficult. At the same time the researches of mobile database are a lot of memory database as the prerequisite, and rarely consider the buffer management; embedded mobile database is not necessarily memory database. With the development of semiconductor technology, a lot of embedded mobile devices are equipped with outer memory to meet the demand for data persistence. Therefore, a new study EMRTDBMS buffer management strategy is necessary.based on embedded, mobile, real-time characteristics of the environment and think carefully about the broadcasting strategy, real-time database system transaction, characteristics of the data, then propose that both client and server buffer management algorithms which regard increasing the buffer page hit rate and improving real-ti-me transaction completed ratio on time as the objective of algorithms efficiency. they are respectively the integrative priority with deadline buffer management algorithm (IntePrio-dl) and the compositive priority with data character and deadline buffer management algorithm (ComPrio-dc&dl), moreover designed the buffer management prototype system of client dbms and server dbms based on linux. Simulatedexperiment shows that the IntePrio-dl and ComPrio-dc&dl are better than some other strategies on buffer pages missing and transaction missing rate.