Simplification of Database Integrity Constraints Revisited: A Transformational Approach

Complete checks of database integrity constraints may be prohibitively time consuming, and several methods have been suggested for producing simplified checks for each update. The present approach introduces a set of transformation operators that apply to database integrity constraints with each operator representing a concise, semanticspreserving operation. These operators are applied in a procedure producing simplified constraints for parametric transaction patterns, which then can be instantiated and checked for consistency at run-time but before any transaction is executed. The operators provide a flexibility for other database enhancements and the work may also be seen as more systematic and general when compared with other approaches. The framework is formulated with first-order clause logic but with the perspective of being applied with present-day database technology.