不完全信息环境下XML Schema规范化研究

Research of Normalization for XML Schema under Incomplete Information Circumstances

为了解决不完全信息环境下XML模式设计中XML文档的数据冗余和操作异常,研究了不完全信息环境下XML Schema的规范化问题,提出了XML Schema和符合XML Schema的不完全XML文档树等概念;基于节点等价、节点相容、节点信息等价和节点信息相容等概念提出了XML强函数依赖的定义,给出了相应的推理规则;给出了求路径集强闭包和成员籍问题的算法,并对算法的正确性进行了证明,对其时间复杂度进行了分析。提出了不完全信息环境下XML范式和相应的规范化算法。研究成果较好地解决了数据冗余问题,避免了更新异常现象,更好地实现了XML

For solving data redundancies and abnormal manipulation for XML documents in schema design under incomplete information circumstances, the normalization theory of XML Schema under incomplete information circumstances was discussed. The concepts of XML Schema and incomplete XML document tree according with XML Schema were formalized. Based on the equivalence of the nodes, the consistency of the nodes, the equivalence of the nodes＇ information and the consistency of the nodes＇ information, XML strong functional dependency^s definition was given,inference rules for XML strong functional dependency were presented. The arithmetic of path set strong closure and membership problem was proposed, its correctness was proved and its time complication was analyzed. The definition of XML normal form under incomplete information circumstances and the corresponding arithmetic of the normalization were formalized. The production in this work removes the redundancies of datum, eliminates update anomalies and achieves better design of XML Schema.