XML的结构完整性约束推理

Reasoning about Structural Integrity Constraints for XML

为了有效地优化XML路径表达式查询,给出了一个XML结构完整性约束体系,这个体系全面描述了XML文档中节点或路径之间的结构关系,包括必需性包含、排他性包含、路径蕴涵、路径互斥和路径同现.在此基础上研究了XML结构完整性约束的逻辑蕴涵和一致性问题.文章首先采用约束重写技术将各种约束改写为路径蕴涵约束;然后给出了一组路径蕴涵的推理规则;最后以路径蕴涵闭包为工具证明了推理规则的完备性并给出了XML结构完整性约束的一致性判断方法.

In order to efficiently optimize XML path expression queries,this paper gives a system of structural integrity constraints for XML（XSICs）.The pattern system provides effective means to specify the structural relationships between different paths or nodes in form of path implication,path concurrence and path mutual-exclusion,element obligatory inclusion,element exclusive inclusion.On the basis of this,the implication and consistency problems of XSICs are studied.Firstly,the technique of constraint rewriting is introduced to rewrite all kinds of constraints into path constraints.Secondly,a set of inference rules for path implication constraints is developed.Finally,the paper proves the completeness of these inference rules,and gives the consistency determinant method of XSICs by using the path implication closure.