1 Adaptive Query Formulation to Handle Database Evolution

Abstract. Databases are continuously evolving environments, where design constructs are added, removed or updated rather often. Research has extensively dealt with the problem of database evolution. Nevertheless, problems arise with existing queries and applications, mainly due to the fact that in most cases, their role as integral parts of the environment is not given the proper attention. Furthermore, the queries are not designed to handle database evolution. In this paper, we introduce a graph-based model that uniformly captures relations, views, constraints and queries. For several cases of database evolution we present rules so that both syntactical and semantic correctness of queries are retained. 1