【摘要】 介绍了在ANGEL这样一个典型的ORDB系统中继承机制的设计思想与实现技术.首先详细阐述系统丰富的继承语义,包括属性继承、约束继承、触发器继承及函数继承,并给出对多重继承所带来各种冲突的处理办法,然后讨论继承机制的实现手段及有关继承机制的模式演变问题.更多还原

【Abstract】 This paper describes the design and implementation of inheritance mechanism in ANGEL, which is a typical ORDBMS. We lay stress on the abundance of semantics about attribute inheritance, attribute constraint inheritance, trigger inheritance and function inheritance. The resolution to different kinds of conflict and schema modification brought forth by multiple inheritance are also discussed.更多还原