Intelligent Information and Database Systems

Volume 6591 of the series Lecture Notes in Computer Science pp 67-77

Certain Answers for Views and Queries Expressed as Non-recursive Datalog Programs with Negation

  • Victor FeleaAffiliated withComputer Science Department, ”Al.I.Cuza” University of Iasi

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In this paper, we study the problem to compute certain answers in case when view definitions are expressed as non-recursive datalog programs with negation and queries are expressed as semi-positive non-recursive datalog programs with negation. Two situations are analyzed: the open world assumption (OWA) and the close world assumption (CWA). Associated to a view, and an extension of the view, a tree is constructed, which is useful to specify a method to compute certain answers.


Datalog program negation query view certain answer