Skyline查询处理数据立方体代数

维空间的Skyline查询处理技术是近年来数据库技术领域的一个研究重点和热点.目前所有的研究工作都是直接在原始数据表上执行关系查询代数操作来获得最终的结果集,然而,随着原始数据表的数据量和维目标个数的增大,这些研究工作将不再适用.基于此,首次研究Skyline集合上的查询代数操作,使得Skyline查询处理的输入数据来自于小规模的Skyline结果集,而非海量的原始数据表.并且,首次给出一个集成多维对象集合和该对象集合上的Skyline结果集的形式化模型,该模型适合目前Skyline查询计算的应用,并在该模型的实例上研究Skyline集合的查询代数操作.同时,给出查询代数体系的代价评估模型.实验表明,给出的数据模型和查询代数体系具有有效性和实用性.

An Algebra for Skyline Query Processing Data Cube

Skyline query processing has recently received a lot of attention in database community. This is mainly due to the importance of skyline result in many applications, such as multi-criteria decision making, data mining and visualization, and user-preference queries. Presently, all the methods get the skyline set by directly executing query algebra operations on the original tables. However, these methods will not be applicable at all when the cardinality of the original tables and the number of dimensions become larger. Motivated by these facts, the query algebra operations on the skyline sets are first studied. The algebra operations only need the input of the skyline query processing to be the skyline sets whose size are much smaller than the original tables. A formalized model is also first proposed, which brings the set of multiple dimensional objects and the result set of skyline query together. And the instances of this formalized model can be used to study the query algebra operations on the skyline sets. Moreover, the cost model of the data model and query algebra operations is proposed. Extensive experiments demonstrate that the data model and query algebra operations are both efficient and effective.