一种支持动态XML文档上关键字查询的索引结构

An Index Scheme for Keyword Search over Dynamic XML Document

在关键字查询领域,目前提出的大多数索引结构主要考虑的是静态的XML文档。当XML文档出现频繁更新时,这些索引结构可能面临着大范围的重新编码,从而增加了数据库索引维护的代价。为了能在XML文档动态更新的环境下保持其索引结构的稳定,提出了一种支持动态XML文档上关键字查询的索引结构DLSS(DDE Level Structure Summary)。该索引结构采用了一种针对动态更新改进的Dewey编码,该编码只需在文档更新时对新的节点赋予相应的编码,而不需要调整原有的编码结构。实验证明,DLSS索引结构可以在XML文档频繁更新或者较少更新时都能保持索引结构的相对稳定,并能在其上实现较高的关键字查询效率。

The index of XML document is important for its retrieval efficiency. The most of existing index schemes for keyword search consider static XML documents. But these indexes will face with widely re-label to in~ the cost for database index maintenance when the XML documents are update frequently. In order to keep the index steady in dynamic environment, propose an index scheme DLSS （ DDE Level Structure Summary ） which applies to keyword search in dynamic XML document. The DLSS is based on an improved Dewey label which gives the new node with corresponding label when the document updates but not to justify the whole index scheme. The experimental results show that the DLSS index scheme not only keeps the index scheme steady in dynamic environment,hut also realizes efficient for keyword search.