On adaptive caching in mobile databases

Abstract

We consider an environment in which a collection of mobile clients accesses a stationary database server via a wireless channel. Due to the limited bandwidth of a wireless channel and the instability of the wireless network, caching of frequently accessed data items in a client's local storage becomes especially important for improving the performance and data availability of data access queries. However, the network stability and high transmission bandwidth requirements of existing caching mechanisms for conventional clientserver and distributed database applications conflict with the mobility nature of mobile clients as well as the low-bandwidth of wireless channel. In this paper, we investigate issues that need to be addressed in caching mechanisms for a mobile environment and propose an adaptive caching mechanism that could cope with the nature of a mobile environment as well as the low-bandwidth wireless media. The results of some preliminary exploratory experiments will also be illustrated to demonstrate the feasibility of our mechanism.