位置相关查询处理的近似回答

位置相关应用在移动计算环境中日趋流行．为了提高系统性能和便于断接操作,可适当放松一些标准来提高可用性．提出了一个使用概括数据库的位置相关查询处理模型,当被访问的原始数据库不合适或不可用时,该查询处理模型能用缓存在移动设备中的概念层次和概括数据库返回近似查询．这个模型提供了在断接期间更优化的数据使用,能有效地利用低的带宽和有限的内存,可提供不同等级查询的近似回答．讨论了包括传输、查询处理代价的性能分析．

Approximate Answers in Location-Dependent Query Processing

Location-dependent applications are becoming more and more popular in the mobile computing environment. To improve system performance and deal with disconnection, some criteria are relaxed to enhance availability. A location query processing model using generalized databases is proposed. When primitive databases accessed are either undesirable or unavailable, this model can return approximate answers using generalized databases and concept hierarchies stored at mobile units. This model provides a more optimal use of data during periods of disconnection and enables efficient utilization of low bandwidth and restricted memory size. This model is able to provide varying levels of approximate answers. Some cost-benefit analyses involving transmission and query processing costs are also discussed.