rapaport@ellie.UUCP (William J. Rapaport) (03/17/86)
UNIVERSITY AT BUFFALO
STATE UNIVERSITY OF NEW YORK
DEPARTMENT OF
COMPUTER SCIENCE
COLLOQUIUM
HANS HERMANN BRUEGGEMANN
Department of Computer Science
University of Dortmund
THE ONE-FLAVOR ASSUMPTION AND GAMMA-ACYCLICITY
FOR UNIVERSAL RELATION VIEWS
A universal relation view is a view on top of a relational
database scheme. In a universal relation view, queries are
expressed without mentioning relation names, and they are
evaluated by using ``window'' functions. We discuss several
design rules for database schemes suited for universal rela-
tion views and formalize one of them, the One-Flavor Assump-
tion. This assumption says that the real-world significance
of any tuple of a window does not depend on the details of
its construction. We prove a deep connection between data-
base schemes satisfying the One-Flavor Assumption and so-
called gamma-acyclic schemes. For such database schemes, we
define the essence of join paths used in the universal rela-
tion system DURST. For universal relation views based on
such schemes, the DURST window functions are essentially
optimized.
Tuesday, March 18, 1986
3:30 P.M.
Bell 338, Amherst Campus
There will be a reception at 4:30 P.M., 224 Bell Hall
For further information, call (716) 636-3181.
--
William J. Rapaport
Assistant Professor
Dept. of Computer Science, SUNY Buffalo, Buffalo, NY 14260
(716) 636-3193, 3180
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