Titlebook: Semantics in Databases; Second International Leopoldo Bertossi,Gyula O. H. Katona,Bernhard Thal Conference proceedings 2003 Springer-Verlag

粗野

Semantics in Databases,e. In computer linguistics or web research, semantics is a component of the language which associates words or components of a grammar with their meaning (linguistic content). In modeling and specification, semantics assigns set-theoretic denotations to formulas in order to characterize truth. At th

演講

HUMID

弄皺

Pedagogy

SLAG

Characterization of Type Hierarchies with Open Specification,ork, such incomplete hierarchies are viewed as .; that is, descriptions which are sets of constraints. The actual hierarchy is then any structure satisfying these constraints. For such specifications, two forms of characterization are provided. The first is algebraic and utilizes a generalization of

organic-matrix

accessory

Consistency Enforcement in Databases,grity constraints. This modification may be done at compile-time or at run-time. The commonly known run-time approach uses rule triggering systems (RTSs). It has been shown that these systems cannot solve the problem in general..As an alternative . (GCSs) have been studied. This approach requires th

腫塊

指耕作

Cardinality Constraints in Disjunctive Deductive Databases,y”, “at most”, or “at least”, respectively, . elements out of the set M have to be chosen..We show how a set . of constraints can be represented by means of a positive-disjunctive deductive database . ., such that the models of . . correspond to the solutions of .. This allows for embedding cardinal