Abstract: The data cache prefetching is a key technology in mobile environments. Cache-Miss-Initiated Prefetch （CMIP） data can improve the system performance by prefetching strategies to access the client record of the history to mining the association rules and get the prefetch data. However, since it does not take account of the data update rate and data size, cache invalidation often takes place. In this paper, this algorithm was based on the data update rate and it increased the size of the selected data to determine and sort, then made the choice of the prefetching data. Through improving, cache invalidation declines and the data access time and power consumption decrease.

Key words: caching, data Prefetch, association rules, update rate

摘要： 数据预取是移动数据库缓存技术中的关键，CMIP预取策略通过客户端历史访问记录关联规则的挖掘得到预取数据，使系统性能得到了提高。但由于没考虑到数据的更新率及数据大小，将会经常发生缓存失效。在此算法的基础上增加对数据更新率及大小的判断并对所选数据排序，然后进行预取数据的选择。通过改进降低了缓存的失效率、减少了数据访问的时间及电能的消耗。

关键词: 缓存, 数据预取, 关联规则, 更新率