A Dichotomy For Non-Repeating Queries With Negation In Probabilistic Databases

This paper shows that any non-repeating conjunctive relational query with negation has either polynomial time or #P-hard data complexity on tuple-independent probabilistic databases. This result extends a dichotomy by Dalvi and Suciu for non-repeating conjunctive queries to queries with negation. The tractable queries with negation are precisely the hierarchical ones and can be recognised efficiently.