Decidable Optimization Problems for Database Logic Programs (Preliminary Report)

TL;DR: This work studies FO-rewritings and their existence for a basic class of queries and for ontologies formulated in Horn DLs such as Horn-SHI and EL and tight bounds on the (worst-case) size of FO- Rewritings, when presented as a union of conjunctive queries.

TL;DR: In this paper, the authors study the FO-rewritability of conjunctive queries in the presence of ontologies formulated in a description logic between EL and Horn-SHIF, along with related query containment problems.

TL;DR: This thesis designs bespoke algorithms based on the Semantic Web standards and traditional Information Retrieval techniques to help smooth out the heterogeneity of large-scale corpora of Linked Data aggregated from millions of sources on the Web in a scalable and robust manner.

TL;DR: This paper presents a new algorithm that computes the perfect rewriting of a conjunctive query w.r.t. a linear Datalog± ontology, and provides an experimental comparison of the algorithm with existing rewriting techniques.