一个面向需求扩展的不确定数据Top-k查询改进算法

已有的不确定数据top-k查询语义只返回在可能世界中聚集概率最大的一个应答,并不能很好地满足用户差异化的查询需求。针对这个问题,通过引入反映查询需求的指标"需求扩展度",定义了基于需求扩展的不确定数据查询语义RU-Topk,并且提出了在新语义下的查询算法。实验表明,RU-Topk算法具有较小的平均单位查询运行时间,且在满足用户需求的情况下,具备更高的查询效率。

Algorithm of Improved Top-k Query on Uncertain Data for Requirement Extension

The semantic of the existing top-k query on uncertain data only returns one response, which has the largest gathered probability in all possible worlds. As a result, it cannot meet the consideration of users' individuation requirement. To address this issue, the concept of requirement extend degree was introduced and a top-k query semantic on uncertain data for requirement extension was defined. Further, an algorithm named RU-Topk to process the semantic was presented. The Experimental results show the superiority of RU-Topk algorithm in terms of run time for per query ansaver and query efficiency compared with the existing algorithms under the condition of meeting users'requirements.