一种基于结构索引的XML模式匹配方法

XML文档采用了树型的数据模型,对其查询通常是用带有选择谓词的模式树在XML数据中进行匹配.因此,找出XML文档中所有符合模式树结构的元素集,是XML查询处理的核心操作.本文提出了结构索引JoinGuide,并在此基础上提出了一种新的XML模式匹配方法.它使用JoinGuide来对模式树进行预匹配,这样在XML文档上查询时可以利用索引上的匹配结果来忽略部分连接谓词和不必要的候选XML元素序列.本文还提出了三种具体算法来利用索引匹配结果进行进一步的查询.实验结果表明本文中的模式树匹配方法优于以往的匹配方法,并且索引所需的空间很小.

A Structural Index Based XML Pattern Matching Approach

XML document employs a tree-structured data model and its queries typically specify patterns of selection predicates to match XML data. So finding all occurrences of such a pattern in a XML document is the core operation of XMLquery processing. In this paper, a kind of structural index called JoinGuide is introduced and then a novel XML pattern matching approach based on it is presented. The approach utilizes joinGuide to pre-match a pattern tree, then when querying XML documents, the pre-match result is used to avoid some join predicates and input XML elements list. Also three algorithms are presented to query XML documents using pre-match result. Experiments show that the approach outperforms the previous ones, and the index size is small.