DifX:利用动态索引体系实现高效的XML数据查询

DifX:A Dynamic Index Structure for Querying XML Data Efficiently

已有的XML数据索引方法从实现思想上可分为两类:结构归纳法和节点定位法·这两种方法都存在一定的问题,结构归纳法的缺点是索引规模较大而且难以有效支持较复杂的查询,而节点定位法的主要缺点是容易形成过多的连接操作·针对这些问题,提出了一种新的动态的XML索引体系DifX,它扩展了已有的动态索引方法,采用一种动态的Bisimilarity的概念,可以根据实际查询需求以及最优化的要求动态决定索引中保存的结构信息,以实现对各种形式的查询最有效的支持·实验结果证明DifX是一种有效而且高效的XML索引方法,其可以获得比已有的XML索引方法更高的查询执行效率·

Traditional index structures for XML data can be divided summary and nodes location approach. There exist some problems for into two categories： the structure both kinds of index structure. The structure summary for XML data often has large size, and performs poorly when processing complicate queries. The primary problem for nodes location approach is that it often causes too many joins in the evaluation of long queries. To solve these problems, a dynamic index structure for XML data, DifX is proposed. By utilizing the notion of dynamic bisimilarity, DifX can efficiently support diverse queries. Experimental results show that DifX is an effective and efficient index structure for XML data, and performs much better than traditional index structures.