多时间粒度下时态函数依赖集的成员籍算法  

An Membership Algorithm for Temporal Functional Dependencies with Multiple Time Graunlarties

作　　者：郝忠孝[1] 姚春龙[1] 

机构地区：[1]哈尔滨工业大学计算机科学与技术学院

出　　处：《计算机工程与应用》2004年第35期183-186,217,共5页Computer Engineering and Applications

摘　　要：为了有效地进行时态数据库设计,支持多时间粒度的时态函数依赖(TFDs)被用于时态模式的规范化。类似于传统的函数依赖(FDs),TFD集的成员籍问题是时态模式规范化所要解决的一个关键问题。由于多时间粒度的使用,使得有成员籍问题变得非常复杂。为了有效地解决此问题,分析了TFDs与FDs之间存在的联系和封闭时态类型集的特性,并且基于提出的有限导出时态类型集及其求解算法,提出一个有效地解决TFD集的成员籍问题的算法。In order to design effectively temporal databases,temporal functional dependencies(TFDs )supporting multiple granularities of time are used to normalize temporal schemes.A crucial problem that needs to be solved for normalization of temporal databases is to compute the membership problem for sets of TFDs.Usages of multiple granularities of time make it very complex to solve the membership problem.In order to solve effectively the problem,relationships between TFDs and FDs and properties of close sets of temporal types are analyzed,and based on the finitely implied set of temporal types and its algorithm proposed,an algorithm for computing effectively the membership problem is given.

关 键 词：时态数据库 数据库设计 规范化 函数依赖 FDS 时态函数依赖 TFDS 成员籍 

分 类 号：TP311.13[自动化与计算机技术—计算机软件与理论]