基于复杂模式索引的XML查询优化  

Query optimization based on complicated scheme indexes

作　　者：于红[1] 王秀坤[2] 高艳萍[1] 张建英[2] 杨南海[2] 

机构地区：[1]大连水产学院信息工程学院,辽宁大连116024 [2]大连理工大学电子与信息工程学院,辽宁大连116024

出　　处：《计算机应用研究》2007年第8期100-105,108,共7页Application Research of Computers

基　　金：国家"973"计划资助项目(2001CCA00700);辽宁省教育厅攻关资助项目(05L090);大连市基金资助项目(2005J22JH038)

摘　　要：分析了XML模式与XML文档之间的关系以及XML查询的特点,提出了一种基于复杂模式索引的XML查询优化方法。该方法对XML模式中的节点建立索引,查询时考虑XML模式中带有环的情况。首先对查询树进行去除重复元素的预处理,并将查询树分解成主路径和分支路径;然后利用索引查找潜在目标节点的XML模式编号;最后在XML文档中对对应节点进行筛选,找到目标节点。该方法可以减少连接操作的次数,提高查询操作的效率,能处理较复杂的XML模式。The paper analyzed XML query and the relationship between XML scheme and XML documents. Proposed a complicated scheme indexbased XML query optimization method. Indexed parent/child node and ancestor/descendant node, took the XML scheme with loop into account. Firstly pretreated the query tree with repetitive labels, then decomposed the query tree into mainpath and branch path. When executed the query, applied the indexes to accelerate the query calculation. This method would reduce greatly number of join, improve the efficiency of query. It could process the complicated scheme. The result of the experiments indicate that the performance of this method is excellent.

关 键 词：复杂模式 索引 扩展标记语言 查询优化 路径表达式 

分 类 号：TP311[自动化与计算机技术—计算机软件与理论]