Update Support for Database Views Via Cooperation

Support for updates to views of database schemata is typically very limited; only those changes which can be represented entirely within the view, or changes which involve only generic changes outside of the view, are permitted. In this work, a different point of view towards the viewupdate problem is taken. If a proposed update cannot be performed within the view, then rather than rejecting it outright, the cooperation of other views is sought, so that in their combined environments the desired changes can be realized. This approach has not only the advantage that a wider range of updates are supported than is possible with more traditional approaches, but also that updates which require the combined access privileges of several users are supported. The key is to model the views as database components. Such components are themselves database schemata, together with distinguished views of their local schemata, called ports, which are used to couple the components together. In the process of realizing an update to a view, the external changes needed for that update are communicated to the neighboring components via the ports. Report: ADBIS2007 page 1, corrected 20070925