Gottlob is currently a chaired professor at the
University of Calabria in Italy where he joined in 2023 due to the "Fantastic Équipe and great potential". Until then, he was a professor of computing science at the
Oxford University Department of Computer Science, where he helped establish the information systems research group. He is also a Fellow of
St John's College, Oxford. Previously, he was a professor of computer science at
Vienna University of Technology, where he still maintains an adjunct position. He was elected a member of the
Royal Society in May 2010. In the area of
artificial intelligence, he is best known for his influential early work on the complexity of
nonmonotonic logics and on
(generalised) hypertree decompositions, a framework for obtaining tractable structural classes of
constraint satisfaction problems, and a generalisation of the notion of
tree decomposition from
graph theory. This work has also had substantial impact in database theory, since it is known that the problem of evaluating
conjunctive queries on
relational databases is equivalent to the constraint satisfaction problem. His work on
XML query languages (notably
XPath) has helped create the complexity-theoretical foundations of this area. ==Awards and honours==