中间件的最优聚集算法
Optimal Aggregation Algorithms for Middleware
摘要：
设D是一个包含N个对象的数据库，其中每个对象有m个字段。对象在m个排序列表中给出（其中第i个列表根据第i个字段排序）。我们的目标是根据单调聚合函数t找到前k个对象，同时最小化对列表的访问。这个问题在几种情况下出现。Fagin（JCSS 1999）特别考虑了它，以聚合多媒体数据库系统中的信息。我们对实例最优性感兴趣，即我们的算法在任何实例上都与任何其他（正确的）算法一样好。我们提供并分析了几个实例优化算法的任务，各种访问成本和模型。
英文摘要：
Let D be a database of N objects where each object has m fields. The objects are given in m sorted lists (where the ith list is sorted according to the ith field). Our goal is to find the top k objects according to a monotone aggregation function t, while minimizing access to the lists. The problem arises in several contexts. In particular Fagin (JCSS 1999) considered it for the purpose of aggregating information in a multimedia database system. We are interested in instance optimality, i.e. that our algorithm will be as good as any other (correct) algorithm on any instance. We provide and analyze several instance optimal algorithms for the task, with various access costs and models.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
