基于关系数据库有效地实现RPE查询  

Efficient Implementing RPE Queries in an RDBMS

作　　者：刘云生[1] 万常选[1] 徐升华[2] 

机构地区：[1]华中科技大学计算机科学与技术学院,湖北武汉430074 [2]江西财经大学信息管理学院,江西南昌330013

出　　处：《小型微型计算机系统》2003年第10期1764-1771,共8页Journal of Chinese Computer Systems

基　　金：江西省教育厅科技项目 (赣教计字 [2 0 0 1] 3 87号 )资助

摘　　要：各种 XML 查询语言的共同特点就是利用正则路径表达式 (RPE)来导航 XML 文档的查询 .本文结合我们提出的一种新的 XML数据的关系存储模式 ,对有效地实现 RPE查询的相关研究工作进行了总结 ,并提出了两个有效地实现包含连接的索引改进归并连接算法 .算法采用索引定位技术、短路技术和预侦技术来减少连接代价 .因此 ,不仅能够在当前上下文计算环境下有效地实现包含连接的计算 。The common feature of the XML query languages is the use of regular path expressions (i.e. RPE) to query XML data. In this paper, we briefly review proposal relational storage schemas for XML documents, which can quickly determine ancestor-descendant relationship between any pair of nodes in the hierarchy of XML data, and effectively supports all query powers in XQuery and keyword searches. We then summary related work for efficient implementation of regular path expression queries based on pre-order lists using an RDBMS. Finally, we develop two algorithms called index improved merge join by using indexing technique, short-circuit technique and pre-spying technique, which are proved to be very efficient by cost analysis. Our algorithms can implement containment joins over the current contexts, and largely avoid useless scanning and seeking over irrelevant fragments of the data for containment joins.

关 键 词：XML关系存储 XML查询 正则路径表达式 包含连接 

分 类 号：TP311[自动化与计算机技术—计算机软件与理论]