【摘要】 主动规则及规则处理机制一直是主动数据库研究的薄弱环节,主要表现为:(1) 语义不够丰富;(2) 缺乏基础语义;(3) 缺乏对规则处理的层次化和结构化的描述.为弥补上述不足,对规则处理机制赋予了丰富的规则延伸语义,根据语义的要求,用规则处理树层次化和结构化地描述规则处理过程对系统状态的影响.新的系统执行模型和扩展后的事务使我们能够提出一种支持丰富语义的规则处理算法.与其他规则处理算法相比,该算法实现了新语义,并利用了递归技术,能更好地吻合规则处理过程.更多还原

【Abstract】 Active rules and its processing mechanism have been the weaknesses in the research area of active database for a long time. The weaknesses were mainly represented: (1) The semantic of rules is not rich enough; (2) Lack of fundamental semantic; (3) Lack of hierarchical and structural description of rule processing. In this paper, in order to make up the above weakness, a rich extending semantic is given to the rule processing mechanism. A rule processing tree is represented to describe the influence of rule processing to the state of system structurally and hierarchically. Based on the new system executing model and the extended transaction model, a rule processing algorithm that supports rich rule semantic can be represented. Comparing with other similar algorithm, the algorithm implements the new semantic. The using of recursive technique makes the algorithm coincide with the rule processing.更多还原