计算机工程与应用2016，Vol.52Issue(17)：84-92,9.DOI:10.3778/j.issn.1002-8331.1512-0261
基于部分求值和热踪编译的Twig查询优化方法
Twig query optimization based on partial evaluation and hot-trace compilation
摘要
Abstract
XML tree pattern query also called Twig query, is the core operation of the XML query. In the study of Twig query algorithm, TreeMatch algorithm is considered to be one of the best Twig query algorithm, since it reduces intermedi-ate results to a great extent. However, in the core operation getNext of TreeMatch algorithm, there are many calculations relying on the Twig pattern. When the number of getNext calls is a lot, the redundant calculation will affect the perfor-mance of TreeMatch algorithm. To obtain higher improvement, this paper proposes a novel optimization method for this algorithm based on partial evaluation and hot-trace compilation. Firstly, the method takes Twig pattern as the invariant to do partial evaluation, and translates the query into a sequence of Twig query machine instructions, which avoids some redundant computation in Twig pattern query process. Secondly, the method does hot-trace compilation optimization for the instruction sequence to achieve more efficiency in interpretive execution. Experimental results show that the efficiency of Twig query will increase by 20%to 60%using the optimization method.关键词
Twig/TreeMatch/部分求值/热踪编译Key words
Twig/TreeMatch/partial evaluation/hot-trace compilation分类
信息技术与安全科学引用本文复制引用
万刚辉,廖湖声,苏航,高红雨,高万辰..基于部分求值和热踪编译的Twig查询优化方法[J].计算机工程与应用,2016,52(17):84-92,9.基金项目
北京市自然科学基金（No.4122011）；国家自然科学基金青年基金项目（No.61202074）。 （）
