An information-theoretic approach to normal forms for relational and XML data
An information-theoretic approach to normal forms for relational and XML data
复制标题
关系数据和 XML 数据范式的信息论方法
DOI：
10.1145/1059513.1059519
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
L. Libkin
中科院分区：
文献类型：
--
作者：
M. Arenas;L. Libkin
规范化作为一种产生良好关系数据库设计的方法是一个很好理解的主题。然而，在其他数据模型中，特别是XML中，也会出现同样的问题，即区分设计良好的数据库和设计不佳的数据库。虽然在关系世界中，良好设计的标准通常是非常直观和明确的状态，他们变得更加模糊，当一个移动到更复杂的数据模型。我们的目标是提供一套工具，用于测试时，数据库设计的条件，指定的范式，对应于一个好的设计。我们使用信息理论的技术，并定义一个衡量的信息内容的元素在数据库中的一组约束。我们首先在关系上下文中测试此度量，为熟悉的范式（如BCNF，4 NF，PJ/NF，5 NFR，DK/NF）提供信息理论的理由。然后，我们表明，同样的措施适用于XML上下文中，这给了我们一个最近推出的XML范式称为XNF的表征。最后，我们看看信息理论的标准，证明规范化算法。
Normalization as a way of producing good relational database designs is a well-understood topic. However, the same problem of distinguishing well-designed databases from poorly designed ones arises in other data models, in particular, XML. While, in the relational world, the criteria for being well designed are usually very intuitive and clear to state, they become more obscure when one moves to more complex data models.Our goal is to provide a set of tools for testing when a condition on a database design, specified by a normal form, corresponds to a good design. We use techniques of information theory, and define a measure of information content of elements in a database with respect to a set of constraints. We first test this measure in the relational context, providing information-theoretic justification for familiar normal forms such as BCNF, 4NF, PJ/NF, 5NFR, DK/NF. We then show that the same measure applies in the XML context, which gives us a characterization of a recently introduced XML normal form called XNF. Finally, we look at information-theoretic criteria for justifying normalization algorithms.