Event Decenting In Active Database And Application

The key that can provide initiative-mechanism in the active database is using detecting and disposing event that can waken DBMS to supervise the state of database system, thereby , we can say that event is headspring of initiative-mechanism. We can distill the composite events (event detection) using the arithmetic in the history events in the event warehouse of active database;the composite can trigger the corresponding action if the composite event matches the rule. With the development of wireless communication in recent years, such as intelligent cell , PDA that is in mobile terminal and insert system that can afford initiative service, but the source that is confined such as the EMS memory and battery in the system, so the arithmetic of event detection has strict request. Through analyzing the preceding event arithmetic, the paper advances that the arithmetic that is based on time-interval and PRI. Using the time-interval avoid the same composite event thathappens many times and triggers the same action again and again, the result waste the source of the system. PRI assures that the most important event can distill when many composite events happen in the system. We also use AWT of Java simulate the arithmetic, and prove that the arithmetic is feasibility. A good arithmetic should be used in the practice environment, then the arithmetic can be proved good or not, so we advance that the technique of the active database is used in the system of fire monitoring systems and put forward the model of the system. The arithmetic must be father amended in practice, so the paper advances that the arithmetic is based on the gliding window technique, the technique can guarantee that the validity of the event and save a lot of source of system. The same class event cannot be progressed operation in the other arithmetic, but it is important in true living. We can use the sign of top and underside in the event that can assure that the same class event can progress operation, namely, the top sign of event expresses the class of event, and the underside sign expresses the order that the same class events that had happened. Because Java has some lots of virtues and the virtues can integrate with active database well. But Java cannot dealwith video file directly due to the patent. The paper used the third party software—GIF Animator to deal with the video file and create the GIF file. The method of Java can read data of every picture. The data includes RBG and frequency of pictures. The system triggers e-mail and sends it to IT system if the result of operation meets the rule that we had constituted, so we can supervise the fire system everywhere at any monuments.