Through the coding method, it conbines XML file with DTD closely, which causes the structure inquiry of XML file firstly transform to inquiry of DTD and thus improves the search efficiency.

• 通过这种编码方法,可将XML文档与DTD紧密结合起来,使得对XML文档的结构查询首先转化为对DTD的查询,提高了查询的效率。