Author(s)

M. Bouneffa & N. Boudjlida

Abstract

. In this paper we present an approach of CASE database schema evolu- tion. We also define a set of schema quality criteria and prove that the evolution process preserves them. Schema evolution is performed by a schema integration process based on assumption management. Before integrating two schemas, relationships or correspon- dences relating their concepts must be identified. Such task is called schema comparison. To do this, our approach combines schema transformation with an interactive process which generates and validates hypothetic correspondences or assumptions. The data schema being viewed as a multi-graph, we classify and apply quality criteria to every node in the graph (local criteria] as well as to the whole graph (global criteria}. 1 Introduction New applications of databases such that CAD (Computer Aided

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