Dissertation > Excellent graduate degree dissertation topics show

Research on Caching Technology of Mobile Database Based on Data Broadcast

Author: JiangJiang
Tutor: ShaoXiongKai
School: Hubei University of Technology
Course: Applied Computer Technology
Keywords: Mobile database Data broadcasting Data cache Failure report Data consistency
CLC: TP311.13
Type: Master's thesis
Year: 2009
Downloads: 38
Quote: 1
Read: Download Dissertation

Abstract

Along with the rapid development of computer technology, mobile communications technology and Internet technology, calculation methods are constantly changing. Today's emerging mobile computing model makes it become possible to access the information they need at any time, any place. However, the inherent mobility of mobile computing environments, the frequent disconnect, low-bandwidth wireless networks, mobile client power limited features but also limited the development of database technology in the mobile computing environment, which is why today's database technology a research focus. Due to the asymmetry of the mobile communication network and requires the user scale is scalable communication unit features, data broadcasting and delivers the information is very suitable for mobile computing environment. But in many cases still requires the user to send various requests to the server through a limited upstream bandwidth. However, the the overly frequent transmission data request will not only cause congestion of the uplink channel waste the limited capacity of the mobile client, how to save bandwidth and power under the premise of effective organization of a number of mobile client sends a data request is a research difficulty. We propose the client classification data requests sent to the server strategy can achieve the purpose of saving the limited capacity of the client. Some data cached in the local mobile database is an important technology that will help reduce the response time of local requests and conservation of limited bandwidth. But mobile client cache size is often limited, when the space is full and then need to add new data, you need a certain replacement policy. How to build an efficient cache replacement strategy to improve the cache hit rate and the maximum degree of reduction Hit loss is an important point. Most of the traditional alternative strategies consider only two factors of the frequency of data access and broadcast waiting time, in fact, there is another important factor worth considering, that is popular in many of the same unit between the client or the degree of concern, Because the focus of most of the other client data is likely to be the Client Access. Considering the frequency of data access, broadcast waiting time as well as factors such as the degree of concern among clients introduce a new cache invalidation policy in effect to a certain extent on the available data prefetch. Since the mobile computing inherent mobility and frequent breaking features of the access line, the mobile client actively or passively with the server Disconnections inevitable. How to maintain the consistency of the data of the mobile client and the server after the disconnect is a research focus of the mobile database, there are many related research, typically is a fixed cycle and the varying period of broadcasting cache invalidation report method, However, these studies mostly committed to the consistency maintenance for short time pick-off case. Void cache and send a test request directly overhead in the text for a long time, disconnect contrast, describes a long disconnect mobile client dynamic selection the cache approach the program, in order to achieve the greatest degree to improve cache performance purposes.

Related Dissertations

CLC: > Industrial Technology > Automation technology,computer technology > Computing technology,computer technology > Computer software > Program design,software engineering > Programming > Database theory and systems
© 2012 www.DissertationTopic.Net Mobile