| 基于特定关系模式下函数依赖集的闭包的研究 |
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| 引用本文： | 肖治军,彭小宁. 基于特定关系模式下函数依赖集的闭包的研究[J]. 怀化师专学报, 2012, 0(5): 27-30 |
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| 作者姓名： | 肖治军 彭小宁 |
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| 作者单位： | 怀化学院计算机科学与技术系,湖南怀化418008 |
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| 基金项目： | 怀化学院重点学科建设项目资助. |
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| 摘 要： | 通过实例研究，定义了一个特定的关系模式，并称它为传递依赖关系模式．在传递依赖关系模式下，得出了计算函数依赖集的闭包中函数依赖的个数的公式，并依照具体实例设计了计算函数依赖集的闭包中所有函数依赖的算法，在此算法中，设计了多种计算属性集所有子集的算法．
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| 关 键 词： | 函数依赖集的闭包 Armstrong公理 子集 |
Study on the Closure of Functional Dependency Set Based on a Specific Relational Schema |
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| Affiliation: | XIAO Zhi - jun, PENG Xiao - ning ( Department of Computer Science and Technology, Huaihua University, Huaihua, Hunan 418008) |
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| Abstract: | This paper defines a specific relational schema that is called transitive dependency relational schema, according tostudying a case. Based on the transitive dependency relational schema, the paper proves a formula for computing the number of functional dependencies in the closure of functional dependency set and designs an algorithm for computing all functional dependencies in the closure of functional dependency set. In the algorithm, the paper also designs some algorithms for computing all subsets of attribute set. |
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| Keywords: | closure of functional dependency set Armstrong＇s axioms subset |
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