摘要
在许多大型信息系统中需要存储大量的历史数据.为了有效地组织这些时间变化数据,可以使用时态函数依赖(TFDs)对时态数据库进行有效地设计.由于多时间粒度的使用,数据库设计算法需要在计算机上实现表示时态类型间的关系的逻辑结构和时态类型间的相关操作.为此提出了细于关系矩阵和封闭的时态类型集,并且对于给定的时态类型集及其细于关系矩阵,给出了一个自动生成它的一个封闭集及封闭集对应的细于关系矩阵的有效算法.通过提出的细于关系矩阵和封闭集算法,可以方便地在计算机上实现时态数据库设计算法需要的时态类型间的细于关系比较和glb操作.
For many large-scale information systems, large numbers of historical data need to be stored. In order to organize effectually the time-varying data, temporal functional dependencies （TFDs） can be used to design effectively temporal databases. Because of usages of multiple granularities of time, it is necessary to implement relevant manipulates among temporal types and a kind of structure that can be used to express relations between temporal types in computers. Therefore, the fine-than matrix and the close set of temporal types are proposed. For given a set of temporal types and its fine-than matrix, an effective algorithm for generating automatically itts a close set and the corresponding fine-than matrix of the close set is given. By the finethan matrix and the algorithm of the close set proposed, the glb manipulate and fine-than comparison between temporal types needed by temporal database design algorithms can be easily implemented on computers.
出处
《小型微型计算机系统》
CSCD
北大核心
2006年第11期2094-2099,共6页
Journal of Chinese Computer Systems
基金
黑龙江省自然科学基金项目(F00-06)资助.
