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全序时态模块模式的TO_TSNF分解问题研究
引用本文:万静,郝忠孝.全序时态模块模式的TO_TSNF分解问题研究[J].计算机科学,2007,34(3):114-118.
作者姓名:万静  郝忠孝
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系,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:在许多时态数据库应用中,都存在着涉及多时间粒度的约束。但是,具有多时问粒度的时态数据库的设计相当复杂,甚至难以实现,而现实世界中的许多应用所涉及到的时态类型集都能满足全序关系。同时,具有全序时态类型集的全序时态模块模式有着良好的特性,因此本文提出了全序时态模块模式、时刻关系模式、全序时态模块投影、全序时态简单候选关键字、全序时态三范式(TO_T3NF)和全序时态简单范式(TO_TSNF)等概念,并给出了全序时态简单范式的分解算法,对其正确性进行了证明,并对时间复杂度进行了分析。

关 键 词:全序时态模块模式  全序时态模块投影  全序时态简单范式  多时间粒度

Research on TO_TSNF Decomposition with Total Order Temporal Module Scheme
WAN Jing,HAO Zhong-Xiao.Research on TO_TSNF Decomposition with Total Order Temporal Module Scheme[J].Computer Science,2007,34(3):114-118.
Authors:WAN Jing  HAO Zhong-Xiao
Affiliation:1College of Computer Science and Technology, Harbin University of Science and Technology, Harbin 150080;2Department of Computer, Qiqihar University, Qiqihar 161006;3College of Computer Science and Technology, Harbin Institute of Technology, Harbin 150001
Abstract:Constraints involving multiple time granularities exist in many temporal database applications.However,design of temporal database with multiple time granularities is fairly complicated,even hard to implement.Temporal type sets involved in many real world applications can constitute one total order of types,and total order temporal module schemes with total order temporal type sets have fine properties.The concepts of total order temporal module scheme,tickwise relation scheme,total order temporal module projection,total order temporal simple candidate key,total order temporal 3NF and total order temporal SNF etc.are given in this paper.The total order temporal SNF decomposition algorithm,the proof for its correction and the time complexity analysis are also given in this paper.
Keywords:Total order temporal module schemes  Total order temporal module projection  Total order temporal SNF  Multiple time granularities  
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