Research Of Mobile Databases Cache Algorithms Based On Mobile Agent

With the developement of the mobile communication technology and being launched into use, a mass of dissemination of mobile computers,it makes plenty of computing nodes connect with the networks during transferring freely.Thus the assumption that is issued by the concept of traditional distributed computing and distributed databases is not suitable。 The concept of mobile computing and mobile databases is generated, and it is a hot research field. The research institution abroad such as Stanford University, Carnegie Mellon University, Purdue University and so on organized special research theme institution, and achieved a lot of applied reseach outcome.Mobile databases technology involves databases, mobile computing, mobile communication technology and so on.This article is based on the characteristic and aim of mobile databases,and a mobile database based on Mobile Agent model is designed.In the essential technology of mobile databases,cache technology occupies a large place.Traditional cache invalidation-report is not suitable for the mobile environments because of the frequent disconnection and mobility of clients.A classical cache invalidation strategy is based on IR. In this paper, classical cache invalidation strategies are analyzed in great detail,and it is found that cache strategy based-on IR has drawbacks in query lantecy and bandwidth utility.So,the author propose an IR-based cache invalidation algorithm,which can significantly reduce the query lantency and efficiently utilize the broadcast bandwidth.Detailed analytical analysis and simulation experiments are carried out to evaluate the proposed methodology. Compared to previous IR-based schemes,this scheme can significantly improve the throughout and reduce the query lantency,the number of uplink request,and the broadcast bandwidth requirements.