An object model at conceptual level to support updatable views on object-oriented databases
نویسندگان
چکیده
منابع مشابه
Updatable Views in Object-Oriented Databases
Object-oriented database systems (ooDBMSs) are supposed to offer at least the functionality available in commercial relational DBMSs of today. One important consequence of this is that they have to provide a separation of the global (conceptual) database schema from the external schema (“subschema”) of a particular task. Views are a mechanism to realize this data independence. In addition, they...
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In contrast to base relations, views are typically not stored permanently, but rather computed on demand. Queries to view relations are modified by query substitution so as to operate on the underlying base relations. Therefore, any update to a base relation propagates automatically to all views defined over it. Conversely, view relations can not be updated freely, since it is often ambiguous h...
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Several models of authorization have been proposed for object-oriented databases supporting diierent levels of granularity. However, these models do not support authorization based on database contents and context. A way of handling context and content-dependent authorization is by using views. In this paper, we present a model of authorization, based on a view model proposed by Bertino 4], tha...
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ژورنال
عنوان ژورنال: Information Sciences
سال: 1996
ISSN: 0020-0255
DOI: 10.1016/s0020-0255(96)00125-9