Semantic foundations for the view update problem

We present a declarative framework for updating views over indefinite databases, that is, databases with null values. The framework follows the standard database approach, which allows for a unique null constant. As the main contributions of the paper, we introduce the concept of an indefinite deductive database as a formal representation of a view over an indefinite database, propose a semantics for indefinite deductive databases, and use it to solve the integrity constraints maintenance and view update problems. To address the last issue, we define several classes of database repairs, with the class of constrained repairs as one of them. Constrained repairs form a narrow class of repairs that avoid arbitrary commitments (are grounded in the deductive database specification and the view update request), aim to change the database “minimally” (satisfy a certain minimality condition we introduced that is attuned to the case of indefinite databases) and, in general, address several problems of earlier solutions to the view update problem.