基于XPath的XML查询优化

XML Query Optimization Based on XPath

随着XML作为Internet上数据表示和交换的标准，如何高效地进行XML数据的查询己经变得越来越重要，许多XML查询语言也随之出现。这些查询语言虽然种类繁多，但都有个共同特征：使用基于XPath数据模型下规则路径表示来查询XML数据。研究表明，当前的关系数据库技术在处理规则路径表示的查询时通常效率不高。 文章在介绍了传统的基于遍历树的方法的基础上重点讨论了基于路径分解的查询处理算法，并对选择连接顺序算法提出了基于动态规划思想的改进，

With the advent of XML as a standard for data representation and exchange on the Internet, querying XML data becomes more and more important. Several XML query Language have been proposed, and the common feature of the languages is the use of regular path expression based on XPath Data Model to query XML data. Research shows that the current relational database technology often inefficient when deal with the regular path expression. This paper first introduce the traditional traversing tree algorithm, and then discuss the query parse algorithm which based on regular path expression, and optimize the structural join order by dynamic programming.