A Study On Knowledge Model And Executing Model Of Active Database

The Database technology is one of the quickest developed fields in computer science.And also,It is applied extensively,which has become to the basis of computer science and application system. And now, Relation Database has been applied extensively.The Active Database technology has become a famous aspact in the study of Database technology.Based on other people's research on this field and the theory of ECA Rule,the author studied and designed the Knowledge model and Executing model of Active Database from the point of Application,in order to extend the model of relation Database.In this way,the ECA rules can be expressed.We designed the logic structures of events,conditions and actions which are the elements of the ECA rules.Acording to the event algebra theory,we made an effective solution for the optimization of the composite events.Moreover,in order to improve the executing efficiency of the executing model,we established the physical structure of the rules.Afer these,we made a language.On the basis of Knowledge Model,we made an executing model which can carry out the active mechanism.In the end,we analyzed the rule processing problem,and gived an effective solution for this problem.