A partition model approach to updating universal scheme interfaces

The updating of relational databases has received extensive attention in the past few years. However, the various methods proposed present two main drawbacks: either the method cannot perform some update because of nondeterminism, or the method is deterministic but leads to counterintuitive results. In this paper, we use partition semantics to study updating in universal scheme interfaces. It is shown that, contrary to other approaches, the main difficulties are due to nondeterminism of deletions. We characterize when a deletion is deterministic or not, and we show how partition semantics allow for choices in certain cases of nondeterminism