Abstract. We consider the setting of ontological database access, where an Abox is given in form of a relational database D and where a Boolean conjunctive query q has to be evalua...
We introduce symmetric Datalog, a syntactic restriction of linear Datalog and show that its expressive power is exactly that of restricted symmetric monotone Krom SNP. The deep re...
A Datalog program can be translated into a system of fixpoint equations of relational algebra; this paper studies how such a system can be solved and optimized for a particular qu...
We consider a near future scenario in which users of a Web 2.0 application, such as a social network, contribute to the application not only data, but also rules which automatical...