摘要
以传统关系数据模型为基础建立了多种时态数据库模型。传统数据库具有一些集合运算:选择、投影、连接、笛卡尔积、差、并和交,这些关系代数只是一种瞬像代数,没有考虑时态关系。本文重点介绍了适合于时态数据库的时态关系代数。结果证明时态关系代数运算与传统关系代数运算是相容的。
Varities of temporal database models are built on traditional relation database models. There are some set operations in traditional database, such as selection, projection, join, Descartes’s accumulate and other aggregation operations. But these relation algebra operations are only a snapshot, but not a temporal relation. It discuss the temporal relation algebra operations fit to temporal database. The conclusion is that the algebra operations of temporal relation and traditional relation are similituded.
出处
《武汉科技学院学报》
2005年第1期48-51,共4页
Journal of Wuhan Institute of Science and Technology
关键词
关系数据库
时态数据库
关系代数
集合运算
Relation Database
Temporal Database
Relation Algebra
Aggregation Operation
