基于Vague关系数据模型的除操作研究

基于Vague集理论的Vague关系数据库由于其所含信息的模糊性，对应于现实世界的多种状态。为此，基于扩展的Vague关系数据模型，研究一种条件受限的Vague除操作实现方法，并给出相应的操作步骤和算法。实例分析结果表明，该实现方法可直接作用于整个Vague关系数据库，无需对Vague关系数据库对应的所有状态逐一进行扫描即可获得正确的操作结果，具有较高的执行效率。

Study of Division Operation Based on Vague Relational Data Model

The Vague relational database which is based on the vague set theory,has a canonical interpretation as a set of regular databases because of the fuzzy information it contains.Aiming at the problem,based on the extended vague relational data model,a constrained vague division operator is discussed,and the corresponding steps and algorithms are given.Example analysis result shows that the key for efficiency resides in the fact that the division operator does not require to make computations explicitly over all the possible worlds,but works directly on the vague relational databases,it has higher execution efficiency.