动态调整移动数据库中失效报告时间窗口的大小

在移动计算环境中，如何维护移动客户机中数据缓存的一致性，是研究的一个热点．广播失效报告是一种有效的方法，但由于不同的环境，不同的时期各种参数的变化，失效报告时间窗口ω的大小如何确定是一个难点．时间窗口ω应随各种参数的变化而不断地进行调整，才能保证网络系统的传输工作在最有效的状态．从理论上推导了失效报告时间窗口ω的计算公式，分析了ω的合理取值，并给出了具体实现的算法．

Dynamic Adjusting the Time Window of Invalidation Reports in Mobile Database

In mobile computing environments,how to keep cache consistent in mobile client is a hot research spot. Broadcasting of invalidation reports is an efficient method,but it's difficult to choose the time window of invalidation reports because parameters are varying with environments and time. The time window of invalidation reports must be adjusted continuously while parameters are being updated, to ensure that the network system is working efficiently. In this paper,the formula for computing the time window of invalidation reports in theory are proposed,the reasonable value is analyzed,and the algorithmic implementation is provided.