Framework of metadata research based on XML

The metadata occupies an important place in the data management system.Because of the importance of the metadata,it is extended to the exploitation and is abstracted a frame model and it's key technologies are discussed stressly.Any data related to the tools is stored in the metadata base in the form of metadata,and the metadata will drive the operation of the tasks.It will make the exploder focus on designing the metadata and its style of relative tools,which makes the process of designing easier,and enforce the flexibility and extension of the system.