Vague数据库Skyline查询技术研究

Study on Skyline Query for Vague Database

Skyline查询处理是近年来数据库领域的一个热门研究方向。由于现实世界中普遍存在着大量不精确、不确定的信息,Skyline查询也随之成为模糊数据处理中的一个重要内容。在已有研究的基础上,讨论了基于Vague关系数据模型的Skyline查询,其用于查询给定Vague关系中的任意元组确定不被该关系中的任意其它元组所支配的程度,并给出了相关的计算公式和查询算法,该算法可直接作用于Vague关系数据库,而无需对Vague关系数据库对应的所有可能性状态逐一进行扫描,具有较高的执行效率。在此基础上,还进一步讨论了带有预选择条件的Skyline查询的计算方法。

Skyline query processing has recently received a lot of attention in the field of database. Due to a lot of information is often imprecise and uncertain in the real world, Skyline queries have become an important content of fuzzy data processing. Based on the existing research, Skyline query processing based on the Vague relational data model was discussed. In this framework,Skyline queries aim at computing the extent to which any tuple of a given relation is not dominated by any other tuples of the same relation. And the corresponding query formula and query algorithm were given. The key for efficiency lies in the fact that the algorithm does not require to make computations explicitly over all the possible worlds, but works directly on the Vague relational databases. On the basis, processing method of Skyline query with preseleetion condition was discussed.