Referential actions (rac's) are specialized triggers used to automatically maintain referential integrity. While their local effects can be grasped easily, it is far from obvious what the global semantics of a set RA of interacting rac's should be. To capture the intended meaning of RA, we first present an abstract non-constructive semantics. By formalizing RA as a logic program P_RA, a constructive semantics is obtained. The equivalence of the logic programming semantics and the abstract semantics is proven using a game-theoretic characterization, which provides additional insight into the meaning of rac's. As shown in previous work, for general rac's it may be infeasible to compute all maximal admissible solutions. Therefore, we focus on a tractable subset, i.e., rac's without modifications. We show that in this case a unique maximal admissible solution exists, and derive a PTIME algorithm for computing this solution. In case a set U of user requests is not admissible, a maximal admissible subset of U is suggested.

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This paper elaborates on the practical aspects of

• Referential Actions as Logic Rules, Bertram Ludäscher, Wolfgang May, Georg Lausen, Proc. of 16th ACM Symposium on Principles of Database Systems (PODS'97).

An extended version can be found in

• Understanding the Global Semantics of Referential Actions using Logic Rules, Wolfgang May, Bertram Ludäscher, ACM Transactions on Database Systems (TODS), 27(4), 2002.