摘要
XML树模式查询(TPQ)是XML查询的核心操作,也是XML查询相关研究的热点.将XQuery语言描述的查询功能尽可能多地包含在XML树模式查询中,有助于提高XQuery程序的执行效率.面向一种扩展的XML树模式,用于实现XQuery语言的查询计划描述语言FXQL中扩展了XML树模式描述功能.同时,提出一种有效的XML树模式提取算法,能够从XQuery语言的for/let子句和return子句嵌套的FLWOR表达式中收集各种结构约束,并将这些结构约束合并成单个XML树模式,而不是基于传统提取算法的多个树模式.该方法扩大了XML树模式查询技术在XQuery语言实现中的应用范围,其算法实现和实验说明了该方法的有效性和实用性.
XML tree pattern query(TPQ)is core operation of XML query which has been studied intensively in recent years.The program execution will benefit from utilizing efficiently holistic tree pattern matching algorithms as much as possible.This paper extends an intermediate language FXQL with representation of XML tree pattern,which is used to implement XQuery language.An effective XML tree pattern extraction algorithm is also proposed.In this algorithm,various structural constraints are collected from the nested FLWOR expressions in both for/let clause and return clause, and merged into an extended XML tree pattern which is represented in FXQL.The tree pattern identified by this approach tends to be used to substitute several scattered tree patterns which extracted by traditional ways.The approach expands the application of XML tree pattern query technology in the implementation of XQuery language.Experiments show its effectiveness and practicability.
出处
《计算机研究与发展》
EI
CSCD
北大核心
2013年第S1期12-22,共11页
Journal of Computer Research and Development
基金
国家自然科学基金青年科学基金项目(61202074)
北京市自然科学基金项目(4122011)
