arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2012.06237cs.DB
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无需全连接计算的多表函数重复性发现

Discovering Multi-Table Functional Dependencies Without Full Join Computation

Ugo Comignani, Laure Berti-Équille, Noël Novelli

摘要:

在本文中,我们研究了发现连接FD的问题,即,在多个联接表上保持的函数依赖关系(FD)。我们利用逻辑推理,选择性挖掘和采样,并表明我们可以发现大多数确切的连接FD从单个表参与的连接,并避免连接结果的完整计算。我们提出了算法,以加快加入FD发现过程和地雷FD的飞行只从必要的数据分区。我们介绍JEDI(Join dEpendency DIsparification),我们的解决方案,发现连接FD,而无需事先计算完整的连接。我们在一系列真实世界和合成数据上的实验证明了我们的方法优于现有的FD发现方法,这些方法需要在发现FD之前预先计算连接结果。我们表明,性能取决于基数和覆盖率的连接属性值:对于连接操作覆盖率低,JEDI与选择性挖掘优于竞争的方法,使用直接的方法的全连接计算的一个数量级的运行时间,并可以发现四分之三的确切连接FD主要使用逻辑推理的一半,其总执行时间平均。对于更高的连接覆盖率,JEDI的抽样精度达到1,平均只有表输入大小的63%。

英文摘要:

In this paper, we study the problem of discovering join FDs, i.e., functional dependencies (FDs) that hold on multiple joined tables. We leverage logical inference, selective mining, and sampling and show that we can discover most of the exact join FDs from the single tables participating to the join and avoid the full computation of the join result. We propose algorithms to speed-up the join FD discovery process and mine FDs on the fly only from necessary data partitions. We introduce JEDI (Join dEpendency DIscovery), our solution to discover join FDs without computation of the full join beforehand. Our experiments on a range of real-world and synthetic data demonstrate the benefits of our method over existing FD discovery methods that need to precompute the join results before discovering the FDs. We show that the performance depends on the cardinalities and coverage of the join attribute values: for join operations with low coverage, JEDI with selective mining outperforms the competing methods using the straightforward approach of full join computation by one order of magnitude in terms of runtime and can discover three-quarters of the exact join FDs using mainly logical inference in half of its total execution time on average. For higher join coverage, JEDI with sampling reaches precision of 1 with only 63% of the table input size on average.

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。

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