Model Generation in  Disjunctive Normal Databases

		Adnan Yahya

Computer Science Department, University of Munich, Munich, Germany
		    and
Electrical Engineering Department, Birzeit University, Birzeit, Palestine



                         Abstract

Algorithms  for computing several classes of models for 
disjunctive normal  databases are presented. We show how 
to efficiently compute minimal, restricted minimal, 
perfect, and stable models. The common feature of the 
advanced algorithms is that they are based on augmenting 
a model generating procedure with a set of hypotheses  
to guide its search for acceptable models and/or to 
interpret negation in clause bodies. The approach is 
shown to be useful for different database applications 
including query answering under different semantics and 
integrity constraint enforcement. The developed algorithms 
are easy to implement and compare favorably with others 
advanced in the literature for the same purpose.