Many web-search queries serve as the beginning of an exploration of an unknown space of information, rather than looking for a specific web page. To answer such queries effectiv...
Uncertain data are inherent in some important applications, such as environmental surveillance, market analysis, and quantitative economics research. Due to the importance of thos...
The emergence of database languages with side effects, notably for XML, raises significant challenges for database compilers and optimizers. In this paper, we extend an algebra fo...
As social networks are becoming ubiquitous on the Web, the Semantic Web goals indicate that it is critical to have a standard model allowing exchange, interoperability, transformat...
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...