Abstract: As the core operation in XML query processing, structural joining consumes a great deal of time. The authors proposed a new approach called labeling scheme for efficient query processing (LSEQ). By decomposing path information, LSEQ avoided recording repeated information and reduced labeling length. Moreover, LSEQ supported the representation of ancestor-descendant relationship, parent-children relationship and sibling relationship between any two nodes. Through storing the path of internal nodes, LSEQ enhanced querying efficiency and avoided structure-joining. The experimental results show that, the LSEQ has advantages in compacting translated SQL and lessening relational database space.

Key words: XML coding, data storage, path expression, data query, query optimization

摘要： 在XML数据查询中，结构连接操作占用了大量时间。针对这个问题，提出一种高效查询的编码方案—LSEQ编码。它将节点路径信息进行分解，避免记录路径的重复信息，减小了编码长度；同时支持节点祖先后代关系，父子关系和兄弟关系的表示。LSEQ编码通过记录非叶节点的路径，在节点查询中避免了结构连接操作，提高了查询效率。实验表明LSEQ编码提高了空间利用率，在查询速度上具有出良好的性能。

关键词: XML编码, 数据存储, 路径表达式, 数据查询, 查询优化