Towards a Dynamic Inconsistency-Tolerant Schema Maintenance

When a relational database schema changes, the questions arises if any integrity constraint is violated by the change. For dynamic schema maintenance, traditional methods to answer this question have several debilities. First, they require that all integrity constraints be satisfied before admitting any update, although extant integrity violations are frequent in practice. Second, they are inefficient for dynamic changes of integrity constraints. Third, they are unflexible wrt safety-critical constraints. Fourth, they usually do not care at all whether an updated schema remains satisfiable. We propose improvements of each of these weaknesses.