| 摘要: |
| 提出了“内涵亏值”与“紧致依赖”的概念,证明了由“紧致依赖”组成的依赖基对于“左部加属性、右部减属性”这一规则的公理系统是无冗余而完整的.由此发现了除Guigues-Duquenne 基以外还有其他无冗余完整依赖基,改变了只有唯一的一个无冗余完整依赖基的传统观念,揭开了寻找多种无冗余完整依赖基以满足多样化需求的序幕. |
| 关键词: 值依赖 Guigues-Duquenne 基 紧致依赖 内涵亏值 数据库 |
| DOI：10.3724/SP.J.1001.2011.03807 |
| 分类号: |
| 基金项目:国家自然科学基金(60775036) |
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| Compact Dependencies and Intent Waned Values |
|
MA Yuan1, ZHANG Xue-Dong2, CHI Cheng-Ying1
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1.School of Software Engineering, Liaoning University of Science and Technology, Anshan 114051, China;2.School of Electronics and Information Engineering, Liaoning University of Science and Technology, Anshan 114051, China
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| Abstract: |
| In this paper, Intent Waned Values and Compact Dependency are proposed as new concepts. It has strictly been proven that a dependent foundation that consisted of compact dependencies is an irredundant and complete dependency basis on an axiom system that includes only one rule: attributes are increased at the left side and reduced at the right side. In this way, another irredundant and complete dependency basis is found, which is distinguished from the Guigues-Duquenne basis. This basis changes the traditional idea that there exists a sole irredundant and complete dependency basis and discloses the prospect of finding multiple kinds of irredundant and complete dependency basis for a variety of requirements. |
| Key words: value dependency Guigues-Duquenne basis compact dependency intent waned value database |
