This paper presents a new approach to maintaining materialized views without accessing the underlying base relations. Views can be made self-maintainable using additional data together with the views. For instance one can replicate auxiliary views of the base relations at the site where the views are materialized to ensure self-maintenance of the views. However, the previous approaches often lead to the replication of the entire base relations, which is not acceptable from the data protection point of view. We propose to represent the base data using tables with variables and a to materialize auxiliary views of such tables in form of conditional tables. Modeling updates of the base data as changes of the assignment to the variables, we can compute the updated views by evaluating the conditional tables with respect to the new assignment of the variables. Our approach avoids the replication of the base data and allows active self-maintenance of views triggered by identified updates of the base data.
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