| FD无内部冲突时的Pek且无α环模式分解 |
| |
| 引用本文： | 赵龄强,郝忠孝,顾照鹏.FD无内部冲突时的Pek且无α环模式分解[J].计算机工程,2008,34(3):81-82,9. |
| |
| 作者姓名： | 赵龄强 郝忠孝 顾照鹏 |
| |
| 作者单位： | 1. 哈尔滨理工大学计算机科学与技术学院,哈尔滨,150080
2. 哈尔滨理工大学计算机科学与技术学院,哈尔滨,150080;齐齐哈尔大学计算机学院,齐齐哈尔,161006;哈尔滨工业大学计算机科学与技术学院,哈尔滨,150001 |
| |
| 摘 要： | 通过分析FD集中F的最小归并依赖集特征，提出了初等归并依赖集和最小归并依赖集，定义了初等最小归并依赖集的弱左部冲突和弱右部冲突、Pek(保持FD集，无损连接且满足初等关键词范式)等概念。讨论了数据库模式分解为初等关键词范式的无α环判定问题，实验证明，在初等归并依赖集D有弱左部或弱右部冲突时，满足Pek的分解具有α环，该分解算法是有效的。
|
| 关 键 词： | 无内部冲突 弱左部冲突 弱右部冲突 初等关键字范式 |
| 文章编号： | 1000-3428（2008）03-0080-02 |
| 收稿时间： | 2007-03-25 |
| 修稿时间： | 2007年3月25日 |
Model Decomposition of Pek Without α-Cycle When Functional Dependency Without Inside Conflict |
| |
| ZHAO Ling-qiang,HAO Zhong-xiao,GU Zhao-peng.Model Decomposition of Pek Without α-Cycle When Functional Dependency Without Inside Conflict[J].Computer Engineering,2008,34(3):81-82,9. |
| |
| Authors: | ZHAO Ling-qiang HAO Zhong-xiao GU Zhao-peng |
| |
| Affiliation: | (1. College of Computer Science and Technology, Harbin University of Science and Technology, Harbin 150080; 2. College of Computer, Qiqihar University, Qiqihar 161006; 3. College of Computer Science and Technology, Harbin Institute of Technology, Harbin 150001) |
| |
| Abstract: | By analyzing the minimum merge dependency set characteristics of F in FD set, the elementary merge dependency set and minimum merge dependency set are presented. Notions of weak left side conflict, weak right side conflict under elementary merge dependency set of F and Pek(join-lossless, FD and Elementary Key Normal Form(EKNF)) are introduced. The scheme decomposition is discussed and the result concludes that when the elementary merge dependency set of F has weak left side conflicts or weak right side conf... |
| |
| Keywords: | without inside conflict weak left side conflict weak right side conflict Elementary Key Normal Form(EKNF) |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
| 点击此处可从《计算机工程》浏览原始摘要信息 |
|
点击此处可从《计算机工程》下载全文 |
