Object projection views in the dynamic relational model

ABSTRACT

User views in a relational database obtained through a single projection ("projection views") are considered in a new framework. Specifically, such views where each tuple in the view represents an object ("object projection views") are studied using the dynamic relational model of [V1,V2], which captures the evolution of the database through consecutive updates. Attribute sets which yield object projection views are characterized using the static and dynamic functional dependencies satisfied by the database. Object projection views are then described using the static and dynamic fd's "inherited" from the original database, and the notion of age-closure [V1]. Finally, the impact of dynamic constraints on the view update problem is studied in a limited context. The paper demonstrates that new, useful information about views can be obtained by looking at the evolution of the database as captured by the dynamic relational model.

REFERENCES

• 1: {A} Adiba, M., Derived relations: a unified mechanism for views, snapshots and distributed data. Proc. 7-th Int. Conf. on Very Large Data Bases (1981), 293-305.
• 2: F. Bancilhon , N. Spyratos, Update semantics of relational views, ACM Transactions on Database Systems (TODS), v.6 n.4, p.557-575, Dec. 1981 [doi>10.1145/319628.319634]
• 3: {CA} Carlson, Arora., The updatability of relational views based on functional dependencies. Proc. IEEE COMPSAC (1979), 415-420.
• 4: Stavros S. Cosmadakis , Christos H. Papadimitriou, Updaies of relational views, Proceedings of the 2nd ACM SIGACT-SIGMOD symposium on Principles of database systems, March 21-23, 1983, Atlanta, Georgia [doi>10.1145/588058.588096]
• 5: {DB1} Dayal, U., Bernstein, P.A., On the updatability of relational views. Proc. Fourth Int. Conf. on Very Large Data Bases (1978), 368-377.
• 6: Umeshwar Dayal , Philip A. Bernstein, On the correct translation of update operations on relational views, ACM Transactions on Database Systems (TODS), v.7 n.3, p.381-416, Sept. 1982 [doi>10.1145/319732.319740]
• 7: Ronald Fagin , Jeffrey D. Ullman , Moshe Y. Vardi, On the semantics of updates in databases, Proceedings of the 2nd ACM SIGACT-SIGMOD symposium on Principles of database systems, March 21-23, 1983, Atlanta, Georgia [doi>10.1145/588058.588100]
• 8: {FSD} Furtado, Sevcik, Dossautes., Permitting updates through views of databases. Inf. Systems 4, 4 (79), 269-283.
• 9: Seymour Ginsburg , Sami Mohammed Zaiddan, Properties of functional-dependency families, Journal of the ACM (JACM), v.29 n.3, p.678-698, July 1982 [doi>10.1145/322326.322331]
• 10: A. Klug, Calculating constraints on relational expression, ACM Transactions on Database Systems (TODS), v.5 n.3, p.260-290, Sept. 1980 [doi>10.1145/320613.320615]
• 11: David Maier, Theory of Relational Databases, Computer Science Pr, 1983
• 12: {T} Todd., Automatic constraint maintenance and updating defined relations. IFIP, 1977, 145-148.
• 13: Jeffrey D. Ullman, Principles of Database Systems, W. H. Freeman & Co., New York, NY, 1983
• 14: Victor Vianu, Dynamic constraints and database evolution, Proceedings of the 2nd ACM SIGACT-SIGMOD symposium on Principles of database systems, March 21-23, 1983, Atlanta, Georgia [doi>10.1145/588058.588105]
• 15: Victor Dan Vianu, Dynamic constraints and database evolution, 1983