基于双时态概念数据模型(BCDM)定义了BCDM中的冗余时间变元,对冗余进行了量化描述,提出一种对时间变元的去冗余绑定思想。介绍了BCDM,并对BCDM中的时间标签进行规范化的组合表达;形式地描述了时间变元在当前事务时间的去冗余绑定操作,并对双时态关系的去冗余绑定操作给出了形式描述;对BCDM中的时间变元的去冗余操作给出了实现算法,并进行了算法分析。
The. paper defines the redundant temporal variables in the BCDM, and then advances a new thought for removing the redundant temporal variables. First, the paper gives the introduetion and description for BCDM and the temporal element in BCDM, as well as the temporal label in the BCDM is expressed with normal assembled form; Later, the binding of the removing on the temporal variables is described formally about CTT( Current Transition Time), as well as the analogous binding in the bitemporal relational; Last, the paper brings Out. and analyses an algorithm for the binding of the temporal variables.