Authors: Gio Wiederhold, Stefano Ceri
Tags: 1983, conceptual modeling, SHAMKANT NAVATHE
The optimal distribution of a database schema over a number of sites in a distributed network is considered. The database is modeled in terms of objects (relations or record sets) and links (predefined joins or CODASYL sets). The design is driven by user-supplied information about data distribution. The inputs required by the optimization model are: 1) cardinality and size information about objects and links, 2) a set of candidate horizontal partitions of relations into fragments and the allocations of the fragments, and 3) the specification of all important transactions, their frequencies, and their sites of origin. The paper develops an optimization model for a nonreplicated data allocation in the form of a linear integer zero-one programming problem; the objective function is the total transaction processing cost. To reduce the complexity, a decomposition heuristic is proposed. A replicated allocation is derived as a heuristic postoptimization of the optimal solution without replication. The model is demonstrated with a small sample database. The demonstration shows not only the feasibility of the approach but also increases one’s insight into the distribution issues. The results were not immediately obvious but are explained in the final discussion.Read the full paper here: https://www.computer.org/csdl/journal/ts
