View Updating Through Active Integrity Constraints

Abstract

Current database systems are often large and complex and the case that a user or an application has full access to the entire database is rare. It is more likely to occur that access is granted via windows of the entire systems, called views. A view, usually virtual, is defined by giving a query on the whole database and at any point the content of the view is just the outcome of this query. Applications query a base relation or a view in the same way. Therefore, querying a view does not represent a serious conceptual problem. In contrast, the issue of view updating is problematic and of paramount importance: it refers to the problem of translating an update request against a view into an update request involving the base of data. Over the years, a substantial amount of research has been devoted to the various issues surrounding view updating and not surprisingly a wide selection of approaches to the view update problem has evolved. See [2,3] for surveys of methods for view updating.