摘要
时态数据处理多是基于关系数据库平台,时态数据库模型也以时态关系数据模型为主.关系数据模型难以处理具有复杂类型的数据对象,而面向对象数据模型还缺乏商业化应用平台.现有关系数据库平台大多增加了面向对象基本功能,形成了对象关系数据库系统,因此将对象关系数据模型进行时态扩充就显得十分必要和具有可行性.首先在现有时态关系数据模型基础上,提出了一种基于对象关系双时态数据模型,而这种数据模型适合于在现有数据库平台上实现;其次,在该模型框架内,讨论了时态对象关系模式与时态关系模式相互间的联系与转换,这也是由时态关系扩充到对象关系的基本要求;再次,分析了时态模型中时态变量复杂语义和相应绑定算法,这是时态数据库能够有效运行的基本课题之一;最后,研究了基于时态变量复杂语义的时态对象关系数据操作代数,从而为时态对象关系模式的查询进行了必要的理论探讨.
The processing of temporal data is based on the platform of relational databases mostly, and temporal data model is an important part in the general temporal data model. It is difficult for relational data model to deal with the data which contains the complex type, and the object oriented data model is short of commercial applied basis. There are extensions to the function, of objects in most relational databases, so it＇ s not only very necessary but also rather feasible to extend the temporal relational data model to the one based on object-relation. Firstly, working on the data model of temporal-relation, a bitemporal data model on object-relation is proposed in this paper, which may be implemented in current object-relational databases. Secondly, the relationship and the transformation between temporal object- relation and the temporal relation are disussed in the model＇ s framework, which is a fundamental requirement of extending temporal data schema to temporal object-relational data schema. Thirdly, the complex semantics of the temporal variables and the corresponding binding algorithm of the variables are discussed, which is one of the keys for the practical operation of temporal databases. Finally, the temporal algebra operations of the temporal object-relation data with the complex semantics in temporal variables are built, which is a significant for the study of the temporal query algorithm.
出处
《计算机研究与发展》
EI
CSCD
北大核心
2007年第11期1971-1979,共9页
Journal of Computer Research and Development
基金
国家自然科学基金项目(60673135
60373081)
广东省自然科学基金项目(05003348)~~
关键词
时态数据模型
对象关系模型
代数运算
面向对象数据模型
关系数据模型
对象关系数据库系统
数据库平台
对象关系模式
bitemporal data model on object-relation
relation and transformation between temporalrelation and temporal object-relation
temporal constraint of object-relation
complex semantics and bindingalgorithm on temporal variables
algebra of temporal object-relation
