Research Of Active Rule Set Confluence Determination Methods Based On CPN Model And The Conditional Formula

In the development and application of database technology,the traditional database changes to the active database.Active database technology has the function of resolving system exception autonomously,can monitor and alarm the database in the modern application.In addition,the active database has to ensure data integrity,consistency and data real-time processing,these characteristics make the active database to be widely applied in today's information management and industrial process control management system,which is the traditional database system not possess.Therefore,using the active database technology to expand and update the traditional database application,the system could be automatically make corresponding strategies about the state of the database without manual intervention.Use the active rule of "events—conditions—action"(ECA)realized the active function of active database.In ECA rules,define the sequence is events,query the database is part condition,modify or query operations on the database data is the action part of the active rule.So active rule execution can be expressed as: Performing a corresponding action when the active database trigger events and reach the condition,Modern application system puts forward the concept of confluence of active rule in order to improve the quality of information.Confluence well not only ensure the quality of the data,also can effectively maintain the consistency of the data.Existing research methods can't have an efficient and comprehensive confluence determination for active rule set under certain conditions,so the main direction of active database research is still analyze and judge the confluence of active rule under specific conditionsPresent active rule confluence determination methods are mostly limited to identify the exchangeability of specified priority rule set,for other confluence determination of the rule set lack of corresponding effective methods;In the existing methods without considering conditions of the existence of conflicts between rules,which cause they are not likely to appear at the same time in the same execution sequence,and without considering whether satisfying the conditions of different rules being dispatched under the same initial state.Now in the study of Petri nets,put forward the corresponding solutions to the termination decision problem of compound event and compound condition rule set,but still lack of an analytical method for judging the confluence of rule sets under compound conditions,so cannot judge the confluence of the rule set effectively.Aiming at these deficiencies,this paper puts forward the concept of exclusive selection rules,confluence prerequisites and bus criterion theorem,given the methods of establish new conditional formula and determine the related confluence.Through theoretical analysis,this method has the ability which existing methods don't have,can decides confluence of rule set which including exclusive selection.Colored Petri Net(Colored Petri Net,CPN for short)is a powerful graphical modeling and tracking function,is widely used to describe the relationship between the computer events.CPN model has the features of easy to use and intuitive,describe the process of the operation in the database system through the graphical way which is better analyzed all kinds of relationships between complex events.Expand existing methods and setting up ECPN model because the active rule set has the ECA active rule.Verified convergence of active rule set algorithm based on conditional formula algorithm through ECPN model.In this paper,used open source Petri net modeling software(CPN Tools)to developing and modeling active rule,finished the ECPN simulation experiment.The result of simulation shows that this model can support the confluence of active rule set analysis well,also verified the correctness and effectiveness of the algorithm in this paper.The method proposed in this paper can provide some effective theoretical basis and experimental verification for database researchers in subsequent active database research.This method also helps to complete the auxiliary analysis of active database system,and promotes the full application of active database in more related fields.