Deriving Production Rules for Constraint Maintainance

TLDR

Traditionally, integrity constraints in database systems are maintained either by rolling back any transaction that produces an inconsistent state or by disallowing or modifying operations that may produce an inconsistent state. The study proposes an SQL-based language and framework to automatically repair inconsistent database states using production rules. The framework translates constraints into production rules that detect violations and trigger operations to restore consistency, with some translation steps automated and others requiring user input, and is demonstrated on a sizable example. We prove that, under certain assumptions, the set‑oriented production rules guarantee that each transaction ends in a state satisfying all defined constraints.

Abstract

Traditionally, integrity constraints in database systems are maintained either by rolling back any transaction that produces an inconsistent state or by disallowing or modifying operations that may produce an inconsistent state. An alternative approach is to provide automatic repair of inconsistent states using production rules. For each constraint, a production rule is used to detect constraint violation and to initiate database operations that restore consistency. We describe an SQL-based language for defining integrity constraints and a framework for translating these constraints into constraint-maintaining production rules. Some parts of the translation are automatic while other parts require user intervention. Based on the semantics of our set-oriented production rules language and under certain assumptions, we prove that at the end of each transaction the rules are guaranteed to produce a state satisfying all defined constraints. We apply our approach to a good-sized example.