Résumé
We consider the containment problem for conjunctive queries with atomic negation. Firstly, we refine an existing algorithm based on homomorphism checks, which itself improves other known algorithms in databases, and analyze it experimentally. Secondly, we present a new algorithm based on the translation of the containment problem into the problem of checking the unsatisfiability of a propositional logical formula, which allows us to use a SAT solver, and we experimentally compare both algorithms.