A number of visionaries would like a metadata repository to be "active" so that if someone made a change to one schema, it would be automatically reflected in any schema to which it was related. What are the problems associated with implementing this functionality? Are there some cases where it simply cannot be done? Are there some reasons that one wouldn't want this functionality? Describe what you think would be the best compromise, that is, the functionality that you think would be most helpful to an organization.