关于面向对象数据库系统中用户视图机制的研究

A Study of User's View Mechanism for an Object-Oriented Database System

面向对象数据库的模式是按照对象信息的内涵制定的,考虑的因素包括对象的分类、概括、综合、聚集及其所描述的不同类型对象间的联系等。然而不同用户对这些复杂信息的覆盖面有不同的要求,且不一定与系统的数据库模式恰好吻合,这就向面向对象数据库系统(OODBS)提出了支持用户视图、进行数据重构的要求。本文就引入用户视图机理到OODB 中的方法进行了探讨,给出了面向对象用户视图的定义与描述,并讨论了与之相关的数据字典信息,最后提出了建立用户视图所应遵循的原则。

A schema of object-oriented database is built upon the intension of object information, such as partition,generalization aggregation,relevance,etc.As different users have different require- ments for these complex information,which will probably not fit in with the basic schema,it is imp- ortant for Object Oriented Database System to allow data reconstruction and support user's views.This paper discusses the definition and description of user's view mechanism.Some data dictionary infor- mation and criteria for setting up user's view are also addressed here.