【作者】 朱华兴；

【导师】 周丽娟；

【作者基本信息】 哈尔滨理工大学 ， 计算机应用技术， 2007， 硕士

【摘要】 近年来,XML(Extensible Markup Language)己经成为互联网上数据发布和数据交换的事实标准。受到越来越多的关注。各行各业都在采用XML来描述本领域的信息,随着XML的普及,人们对XML文档查询的要求会越来越高。因此如何提高查询时的效率成了一个亟待解决的问题。虽然XML查询技术已经取得一些研究成果,但由于XML文档自身的特点,以及它与传统数据模型的差异,XML查询技术在理论上和实现上都还存在很多难点。本文对XML查询技术进行深入研究,对XML数据查询算法研究现状、发展以及应用进行了分析和总结,详细分析了XML查询技术;研究XML数据库的发展、功能、结构、特点和主流技术,包括传统关系型数据库的XML扩展和纯XML数据库;分析XML文档在数据库中的存储方式,提出混合型XML存储结构,支持结构化和非结构化双向转换,提高XML文档的操作效率。目前已经提出了多种查询XML数据的方法,然而随着多处理器系统和多核心处理器系统的流行,传统的XML查询方法不能充分利用多处理器和多核心处理器的优势。本文详细阐述了并行计算理论,并行计算机系统的体系结构,并根据并行计算理论和XML查询技术,设计采用分治范例和工作池相结合的并行范例。选取XML处理模型,设计并行粒度,构造并行性,提出基于树匹配算法的XML数据并行查询算法,大幅提高了共享存储器多处理器、多核心处理器系统中XML数据的查询效率,并进行性能分析。更多还原

【Abstract】 Recently, XML (Extensible Markup Language) has become new standard of data representation and exchange on the Internet and has been accepted in many fields, getting more and more attention. With wide adoption and development of XML as a description language for document and information, people will have more requirements for performance of XML query. Therefore, how to improve the query efficiency for XML has been increasingly important.Although great achievements of XML research have been made, there are many problems of XML query technology because of XML inherent characteristics and the differences from traditional relational data model. This paper focuses on XML queries, sums up the current status and developing, analyzes the methods of querying XML in detail. The developing, functions, structure, features and mainstream technology of XML database, including conventional XML-Enabled DBMS(XED) and Native XML DBMS (NXD), Storage modes of XML are disscused in XML database.It proposes a mixed XML storage structure, supporting bidirectional conversion storage structure between structurized data and nonstructured data, improving the efficiency of XML query.Many evaluation methods for XML queries are proposed recently. However, with the popularity of multiprocessor and multi-core processor computer system, these conventional approaches fail to use the advantage of multiprocessor and multi-core processor. In this paper, we discuss theory and of parallel computer and design a parallel paradigm using divide-and-conquer paradigm and working pool paradigm. By selecting XML processing model, designing parallel granularity and parallelism, we propose a new parallel algorithm for XML query using matching algorithm of tree, which largely improve the efficiency of XML query processing in shared memory multiprocessor and multi-core processor computer system and make a performance test.更多还原