移动数据库自适应缓存失效算法的研究

在移动客户端建立缓存可以提高移动数据库系统的性能,也会带来服务器上的数据和缓存中的数据不一致的问题,即缓存一致性问题.通常采用基于广播的缓存失效算法来维护缓存的一致性.传统的采用同步广播方式或异步广播方式的缓存失效算法各有优缺点.该文在分析传统算法优缺点和一些现有算法的基础上,提出了一种改进的基于计数器的自适应缓存失效算法,该算法结合了两种传统的算法,可以提高缓存的利用率,同时可以降低通信开销.

The Research of Adaptive Cache Invalidation Algorithms for Mobile Database

Mobile Client Cache can improve the performance of the mobile database system.However,it leads to the problem that data in server and in cache are not consistent,that is,cache inconsistency problem.People often maintain the cache coherency through the cache invalidation algorithms based on broadcasts.Conventional cache invalidation algorithms based on synchronous broadcasts or asynchronous broadcasts have both advantages and disadvantages.The paper discusses the conventional algorithms and some existing algorithms and puts forward an improved adaptive cache invalidation algorithm based on counters,it integrates the two conventional algorithms,and it can improve the cache utilization rate and reduce the communication overheads.