基于编码的XML关系数据库存储

在XML的发展过程中，如何有效地利用关系数据库技术存储和查询XML数据已经成为一个研究热点．提出了一种基于前、后序编码的XML关系数据库存储方法，该方法采用的模式映射方法能够使基于不同DTD（或schema）的XML文档保存在同一个关系表中，支持快速的XML路径查询，且具有较高的XML文档重组效率．对该方法中递归模式的处理技术也进行了讨论．实验表明，与XRel，Florescu和Kossman等人提出的XML关系数据库存储方法相比，该方法能够缩短复杂XML路径查询（如带条件谓词约束的路径查询）的响应时间．

Numbering Scheme Based Relational Storage of XML Documents

With the prevalence of XML, how to make use of RDB to store and query XML documents has become a hot topic and many methods of relational storage of XML documents are proposed. A common object of these methods is to improve the efficiency of XML path query. In this paper, a numbering scheme based relational storage of XML documents is proposed, in which XML path query can be quickly done. Moreover, with this XML storage method, XML documents conforming to different DTD (or schema) can be kept in a same relational table and XML document reconstruction can be done with linear time complexity. Recursive schema handling is also discussed. Experimental results demonstrate that this method can process general path queries, such as path with predicate constraint, faster than methods proposed by XRel, Florescu and Kossman.