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Referential actions as logical rules
 In Proc. PODS'97
, 1997
"... Referential actions are specialized triggers used to automatically maintain referential integrity. While their local behavior can be grasped easily, it is far from clear what the combined e ect of a set of referential actions, i.e., their global semantics should be. For example, di erent execution o ..."
Abstract

Cited by 8 (2 self)
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Referential actions are specialized triggers used to automatically maintain referential integrity. While their local behavior can be grasped easily, it is far from clear what the combined e ect of a set of referential actions, i.e., their global semantics should be. For example, di erent execution orders may lead to ambiguities in determining the nal set of updates to be applied. To resolve these problems, we propose an abstract logical framework for rulebased maintenance of referential integrity: First, we identify desirable abstract properties like admissibility of updates which lead to a nonconstructive global semantics of referential actions. We obtain a constructive de nition by formalizing a set of referential actions RA as logical rules, and show that the declarative semantics of the resulting logic program PRA captures the intended abstract semantics: The wellfounded model of PRA yields a unique set of updates, which is a safe, sceptical approximation of the set of all maximal admissible updates � the third truthvalue unde ned is assigned to all controversial updates. Finally, we show howtoobtaina characterization of all maximal admissible subsets of a given set of updates using certain maximal stable models. 1
Referential actions: From logical semantics to implementation
 IN PROC. OF THE CONF. ON EXTENDING DATABASE TECHNOLOGY (EDBT
, 1998
"... Referential actions (rac's) are specialized triggers used to automatically maintain referential integrity. While their local e ects 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 ..."
Abstract

Cited by 2 (1 self)
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Referential actions (rac's) are specialized triggers used to automatically maintain referential integrity. While their local e ects 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 rst present an abstract nonconstructive semantics. By formalizing RA as a logic program PRA, a constructive semantics is obtained. semantics is proven using a gametheoretic 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 modi cations. We showthat in this case a unique maximal admissible solution exists, and derive aptime algorithm for computing this solution. In case a set U of user requests is not admissible, a maximal admissible subset of U is suggested.
Understanding the Global Semantics of Referential Actions Using Logic Rules
 ACM Transactions on Database Systems (TODS
, 2002
"... Properties. Given RA, D, and U # as above, a set #={del R 1 (x 1 ), ...,del R n (x n )} of delete requests is called founded, if for all del R(x)##, there is a #del R (x # )#U # s.t. (R(x), R # (x # )) # (note that here, we need reflexivity for covering R # (x # ) itself), complete,if del ..."
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Properties. Given RA, D, and U # as above, a set #={del R 1 (x 1 ), ...,del R n (x n )} of delete requests is called founded, if for all del R(x)##, there is a #del R (x # )#U # s.t. (R(x), R # (x # )) # (note that here, we need reflexivity for covering R # (x # ) itself), complete,if del R P (y)##and (R C (x), R P (y)) feasible, if (i) (R C (x), R P (y)) implies del R P (y) / ##, (ii) del R P (y)##and (R C (x), R P (y)) admissible, if it is founded, complete, and feasible.