Design And Implementation Of A Mobile DBMS With Multiversioned-DBS

The uniting of embedded system and telecommunication technologies generates a bran-new computing mode: mobile computing. In mobile computing environment, user can access information with pocket equipment though wireless connections regardless of the location and the time, even the movement of the user. Of all the mobile computing technologies, mobile DBMS is a very important branch. As a result of the mobile computing environment, mobile DBMS must have the ability to support mobility, high bandwidth variability, disconnection, and low bandwidth, which traditional DBMS can hardly deal with. Therefore, it necessitates the research of new solutions according to the characteristic of mobile computing environment.This thesis starts with the analysis of the characteristic of mobile computing environment,witch is followed by the introduction of some important concepts of mobile DBMS and the review of the important technologies in this field.Based on these proven technologies, a thorough discussion of the generation, detection and resolution of conflict is put forward. First, due to the conflict caused by the W-R operations, the thesis gives reason of how the conflict generates and the possible detection method. Then according to the W-W types of the conflicts, this thesis brings forward a view of how to sort the conflicts, and provide the resolution strategies of each type.The clou of this thesis is the improvement of the concurrency capability in mobile DBMS. This thesis presents the advantages of a snapshop isolated multi-version DBMS as the DBS and proposes a solution of the concurrency difficulty when using the multi-version DBS, according to the requirement of the mobile DBMS and the characteristic of multi-version DBMS. Then this thesis gives the proof of the solution's validity.Moreover, to deal with the fact that the mobile computing environment is lack of security and reliability, this thesis proposes the data security and failure recovery solutions to improve the usability of the mobile DBMS.Last, this thesis provides a complete design of an applied mobile DBMS. This design gives all the detail of a mobile DBMS system, including the data security and failure recovery solutions and the multi-version DBS concurrency scheme. With the design in this thesis, my project team has already implemented synchronization system of a mobile DBMS, successfully initialized the system and carried out the multi-user synchronization.