University of Oxford Logo University of OxfordDepartment of Computer Science - Home
On Facebook
Facebook
Follow us on twitter
Twitter
Linked in
Linked in
Flickr
Flickr
Google plus
Google plus
Digg
Digg
Pinterest
Pinterest
Stumble Upon
Stumble Upon

REQUIEM: Resolution-based Query rewrIting for Expressive Models

REQUIEM (REsolution-based QUery rewrIting for Expressive Models) is a prototypical implementation of a query rewriting algorithm recently developed by Héctor Pérez-Urbina, Boris Motik, and Ian Horrocks at the Department of Computer Science, University of Oxford (see publications).

Given an ELHI TBox and a conjunctive query, REQUIEM computes a datalog query that is a rewriting of the query w.r.t. the TBox. REQUIEM produces worst-case optimal rewritings: if the TBox is in ELHI, ELH or EL, then the rewriting is a datalog query; if the TBox is in DLlite+, then the rewriting consists of a union of conjunctive queries and a linear datalog program; and if the TBox is in DLliteR, then the rewriting is a union of conjunctive queries. Existing (deductive) database technology can be used to evaluate the rewriting over any ABox.

REQUIEM can be run in three modalities: the Naive modality, which corresponds to the original algorithm; the Full modality, which applies forward/query subsumption and dependency graph pruning, and the Greedy modality, which applies the optimizations of the Full modality plus greedy unfolding (only useful for EL ontologies) (see Using REQUIEM).

See: The project home page for more details.

Links

Project Home Page

Info

Duration

People

Themes