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上海电力大学学报:2002,18(1):38-40
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关系模式中候选码的求解
(上海理工大学 计算机工程学院, 上海 200093)
Evaluation to Candidate Keys to Relational Model
(College of Copmputing Engineering, Uninversity of Shanghai for Science and Technology, Shanghai 200093, China)
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投稿时间:2001-05-22    
中文摘要: 关系数据库模型的应用十分广泛,其候选码的求解已被证明是一个NP完全问题,从闭包的角度讨论了如何求解候选码,并对其求解过程进行了一定程度的优化.最后提出了一些比较合理的建议.
中文关键词: 关系模式  候选码  闭包  函数依赖
Abstract:Relational database model is used widely. It is proved that finding all candidate keys of a relational model is an NP problem. This artical mainly discusses how to evaluate all candidate keys to a relational model by using closures, and optimizes the finding procedures to a certain extent, finally also proposes some advice on evaluating the candidate keys.
文章编号:20020109     中图分类号:    文献标志码:
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引用文本:
张永,顾国庆.关系模式中候选码的求解[J].上海电力大学学报,2002,18(1):38-40.
ZHANG Yong,GU Guo qing.Evaluation to Candidate Keys to Relational Model[J].Journal of Shanghai University of Electric Power,2002,18(1):38-40.