一种基于XML文档关键字检索的结构索引

XML数据索引对其检索效率有较大的影响。在深入分析现有XMI、结构索引之后，结合XML文档特点，提出了一种基于关键字检索的结构索引--LSS(Level Structure Summary) . LSS采用了把具有相同标签路径的结点进行合并的策略，具有高效判断结点之间同构异构关系的能力。实现了LSS索引生成算法CSCAN，并在LSS索引的基础上设计了XML关键字检索算法LSSearch。该算法依据LSS索引，将各个关键字的原始倒排表集合分拆成不同类型的子集合，最后在所有子集合上进行查询。实验结果表明，LSS可以帮助减少XML文档中关键字倒排表的规模，提高检索效率。

Structure Summary for Keyword Search over XML Documents

The index of XML Data is crucial for retrieval efficiency of XML document After analysis of existing XML structure summaries, this paper proposed a structural summary over keyword search called LSS combining the XML document. I_SS merges the nodes in the XMI_ tree with the same label path so as to determine nodes' homogeneity and heterogeneity efficiently. This paper implemented LSS constructing algorithm called CSCAN, and designed a XML keyword retrieval algorithm called LSScarch based on LSS. hhis algorithm split keywords' inverted list into different type subsets,finally retrieved to get all results quickly on these subsets. Experimental results demonstrated that I_SS can help to reduce the size of the keyword inverted list in XML document dramatically and improve retrieval efficiency.