摘要
不完全信息问题存在于每一种数据库模型中。传统的二值逻辑难以适应不完全信息处理的需求,而多值逻辑能更多地捕获不完全信息的直觉含义。在关系数据库系统的实现中,对不完全信息的处理通常采用三值逻辑。为满足实际应用的需要,本文选取了适用于不完全信息处理的一组联结词∧、∨、→、和μ作为构造逻辑系统的原始联结词。构造了一种新的三值逻辑命题演算系统M PM和三值逻辑谓词演算系统M FM,证明了其可靠性和完备性,并给出了在查询优化方面的应用。M FM可作为研究不完全信息数据库理论的逻辑基础。
The problem of incomplete information exists in every kind of database model. The traditional two-valued logic is difficult to deal with incomplete information while the multi-valued logic can capture more intuitive meanings. When a relational database system is implemented, three-valued logic is usual ly adopted to handle incomplete information. To meet the application needs of the incomplete information da（abase, based on original connectives ∧、∨、→、┐ and μ, a new three-valued logic propositional calculus system MPM and a new three-valued logic predicate calculus system MFM are constructed. Furthermore, the soundness and the completeness of the MFM are proved. Finally, its applications to query optimization are given. MFM is regarded as a logical foundation for the theory of the incomplete information database.
出处
《南京航空航天大学学报》
EI
CAS
CSCD
北大核心
2006年第6期679-686,共8页
Journal of Nanjing University of Aeronautics & Astronautics
基金
南京大学计算机软件新技术国家重点实验室开放课题基金资助项目
关键词
不完全信息
三值逻辑
空值
命题演算
谓词演算
incomplete information
three-valued logic
null
propositional calculus
predicate calculus
