基于DOM的XML数据库的索引技术研究

XML作为一种数据交换的国际标准，已经贯穿于Internet应用的各个领域之中，如何快速准确地存储和查询XML数据的数据库技术是一个重要的研究课题。XML索引技术对XML数据库查询处理起着至关重要的作用，提出了基于DOM的XML数据库的索引技术(路径连接索引、值索引和引用索引)，解决了传统的基于树的遍历的XML数据查询方法性能上的不足，并着重对处理含有谓词和引用关系等较复杂的查询路径的不同处理方法进行了对比和分析，还给出了索引空间利用率、查询性能和索引维护代价3个方面的标准测试结果，表明新的索引技术可以有效地提高查询处理效率。

Study of Index Techniques for DOM-Based XML Databases

As an international standard of data exchange over the Web, XML has penetrated virtually all fields of Internet applications. How to store and query the XML data with database quickly and precisely is an important research topic. Indexing techniques for XML data are very important to enhance XML database query processing. In this paper, several index structures, including path join index, reference index and value index, for DOM-based XML data query processing are proposed, in order to solve the problem of the poor performance of conventional tree traversal approaches. Comparisons and analyses among the different processing approaches for complicated RPE with predicates and/or reference relations are conducted. The detailed performance evaluation results obtained by using typical benchmark experiments are also given to analyze the space utilization, support for queries, and maintenance overhead. The results show that the new index techniques can effectively enhance the query performance in XML databases.