ALICE: an assertion language for integrity constraint expression

Abstract

A declarative constraint language, ALICE, for the expression of complex, logic-based constraints in an object-oriented database environment is presented. The translation of ALICE constraints to logic was developed to support a design approach that uses techniques from deductive databases to explain constraints at design time and to specify propagation actions. Two different translations for ALICE constraints are described: one that allows a relaxed interpretation in the presence of null values and one that enforces a stricter interpretation in which the use of null values is limited. An important contribution of ALICE is that the formal, declarative nature of the language forms the basis of a constraint management facility for intelligent object-oriented database environments.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>