Integrity Checking for Uncertain Data

The uncertainty associated to stored information can be put in direct correspondence to the extent to which these data violate conditions expressed as semantic integrity constraints. Thus, imposing and checking such constraints provides a better control over uncertain data. We present and discuss a condition which ensures the violation tolerance of methods for integrity checking. Usually, such methods are supposed to work correctly only if all constraints are satisfied before each update. Applied to express and check conditions about uncertain data, violation tolerance means that stored data the uncertainty of which violates integrity can be tolerated while updates can be safely checked for introducing violations of constraints about uncertainty. We also discuss the soundness and completeness of violation-tolerant integrity checking and assert it for several methods.