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    张 彬, 蒋 涛, 高云君, 乐光学. 度量空间中的Top-k反向Skyline查询算法[J]. 计算机研究与发展, 2014, 51(3): 627-636.
    引用本文: 张 彬, 蒋 涛, 高云君, 乐光学. 度量空间中的Top-k反向Skyline查询算法[J]. 计算机研究与发展, 2014, 51(3): 627-636.
    Zhang Bin, Jiang Tao, Gao Yunjun, Yue Guangxue. Top-k Query Processing of Reverse Skyline in Metric Space[J]. Journal of Computer Research and Development, 2014, 51(3): 627-636.
    Citation: Zhang Bin, Jiang Tao, Gao Yunjun, Yue Guangxue. Top-k Query Processing of Reverse Skyline in Metric Space[J]. Journal of Computer Research and Development, 2014, 51(3): 627-636.

    度量空间中的Top-k反向Skyline查询算法

    Top-k Query Processing of Reverse Skyline in Metric Space

    • 摘要: 不同于传统的度量空间Skyline查询,提出了一种新颖的度量空间中的Skyline查询MkRS(metric top-k reverse skyline).MkRS从反向角度执行度量空间中的Skyline.给定查询对象q和单调参考函数f,MkRS返回k个包含m个数据对象的子集,以至于每个子集G的度量Skyline包含q.评估这种查询,需要执行从输入数据集P中n个数据对象里选择m个对象的穷举搜索以及每个排列子集的度量Skyline.这些计算由于巨大的搜索空间而需要极高成本.提出了基于排序机理的算法STS(sort and threshold skyline),它可以提前终止计算,仅需要检查很少部分的子集.然后,利用信息重用技术给出了基于重用的STS算法rSTS(reuse STS),进一步减少了STS中80%以上的I/O访问.大量的实验表明提出的算法有效、快速.

       

      Abstract: Unlike the traditional metric skyline query, this paper studies a novel skyline query in metric space, called metric top-k reverse skyline (MkRS), which executes the skyline computation from a reverse perspective. Given a query object q and a monotonic preference function f, MkRS returns k subsets which contain exactly m objects of the input dataset P such that each subset G has q in its metric skyline. When evaluating the query, we need to perform exhaustive search of selecting m objects from n objects of dataset P and metric skylines for each combination. These computations are costly due to the extremely large search space. We first present STS (sort and threshold skyline) algorithm to speed-up the computation, which exploits the sorting machinery so that only a part of subsets needs examining and STS can early stop the computation. Then, we reuse the information produced during index accessing which reduces more than 80% I/O accesses of STS and propose the customized algorithm rSTS based on STS. The experimental results show that our proposed algorithms are effective and efficient.

       

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