Section: New Results
Processing Conjunctive Queries with Negation
Participants : Marie-Laure Mugnier, Michel Leclère, Khalil Ben Mohamed, Michaël Thomazo.
Conjunctive queries have long been recognized as the basic queries in database and knowledge-based systems. The fundamental decision problems on these queries, namely query inclusion checking (given two queries
In collaboration with: Geneviève Simonet (LIRMM Algeco team)
-
Research Report [65] . Long version accepted at Information and Computation.
On the other hand, we have proposed, refined and compared experimentally several algorithms. This study follows first results of us in [61] and is the core of Khalil Ben Mohamed's PhD thesis defended in December 2010 [64] .
-
Results published DEXA 2011 [24] (extending our work in RFIA 2010 [48] , DEXA 2010 [46] , AIMSA 2010 [47] ).
Let us point out that both theoretical and practical results still hold when the predicates are preordered, which allows to take very light ontologies into account, i.e., where concepts and relations are organized in a specialization preorder.