PODS
2010
ACM
14 years 5 months ago
2010
ACM
The notion of certain answers arises when one queries incompletely specified databases, e.g., in data integration and exchange scenarios, or databases with missing information. W...
LPNMR
2009
Springer
14 years 7 months ago
2009
Springer
Abstract. We study the complexity of consistency checking and query answering on incomplete databases for languages ranging from non-recursive Datalog to disjunctive Datalog with n...