Database design aims to find a database schema that permits the efficient processing of common types of queries and updates on future database instances. Full first-order hierarchical decompositions constitute a large class of database constraints that can provide assistance to the database designer in identifying a suitable database schema. We establish finite axiomatisations of full first-ord...

Article history: Received 19 February 2009 Received in revised form 28 October 2011 Accepted 21 December 2011 Available online 23 December 2011

Fuzziness in databases is used to denote uncertain or incomplete data. Relational Databases stress on the nature of the data to be certain. This certainty based data is used as the basis of the normalization approach designed for traditional relational databases. But real world data may not always be certain, thereby making it necessary to design an approach for normalization that deals with fu...

(c) A multivalued logz'c in which truth values are in the interval (O, 1 J and the valuation of a disjunction is the maximum of the disjuncts, whilst that of a conjunction zs the minimum of the conjuncts. This narrow definition encompasses the population stereotype of a 'fuzzy logic' [4-9]. It is interesting that most infinitely-v~ued MVLs [13] have min/max connectives for conjunction/disjuncti...

Multi-valued logics can be effectively used to reason about incomplete and/or inconsistent systems, e.g. during early software requirements or as the systems evolve. In our earlier work we identified a useful family of multi-valued logics: those specified over finite distributive lattices where negation preserves involution, i.e., , , -/.0for every element of the logic. Model-checking over this...