XML DTD的一种范式

A Normal Form for XML DTD

研究了XMLDTD的规范化问题 由于DTD在设计上存在不足之处 ,DTD中可能包含类似于关系数据库模式中存在的异常依赖 ,从而导致XML文档包含冗余的数据和各种操作异常 提出了关于DTD的多值依赖的概念 ,然后基于多值依赖的概念 ,提出了一种XML的范式XNF ,并且用DTD的关系表示形式给出了关于DTD的无损联接分解的概念

The normalization problem of XML DTD is studied XML documents may contain redundant information and operation anomalies due to a bad designed DTD which implies the similar dependencies among elements and attributes just as in relational database schemas The concept of multi valued dependency for XML DTD is proposed And then XNF, an XML normal form, is defined based on the concept of multi valued dependency The concept of lossless join decomposition for DTD is defined by the relational representation of DTD Finally, a lossless join decomposition algorithm for transforming a DTD into XNF is given