Jelle Hellings

Jelle Hellings visiting Indiana University, Bloomington

Teaching assistant and PhD student
Databases and Theoretical Computer Science
Hasselt University, Belgium

Address: Campus Diepenbeek
Agoralaan Gebouw D
BE 3590 Diepenbeek, Belgium
Office:C154

Current research: the study of graph structured data. Recent topics included query optimization, the expressive power of graph query languages on trees and chains, functional constraints for semi-structured data, and external memory index building for XML data and directed acyclic graphs.

Papers

DBPL 2017
From relation algebra to semi-join algebra: an approach for graph query optimization (paper, local version, slides). Jelle Hellings, Catherine L. Pilachowski, Dirk Van Gucht, Marc Gyssens, Yuqing Wu. The 16th International Symposium on Database Programming Languages (DBPL 2017). 2017.
DBPL 2015
Relative Expressive Power of Downward Fragments of Navigational Query Languages on Trees and Chains (paper, local version, slides). Jelle Hellings, Marc Gyssens, Yuqing Wu, Dirk Van Gucht, Jan Van den Bussche, Stijn Vansummeren, George H. L. Fletcher. The 15th International Symposium on Database Programming Languages (DBPL 2015). 2015.
AMAI 2015
Implication and axiomatization of functional and constant constraints (paper, local version). Jelle Hellings, Marc Gyssens, Jan Paredaens, Yuqing Wu. Annals of Mathematics and Artificial Intelligence. 2015. (see also: FoIKS 2014).
arXiv.org 2015
Path Results for Context-free Grammar Queries on Graphs (local version, arXiv.org). Jelle Hellings.
ICDT 2014
Conjunctive Context-Free Path Queries (paper, local version, slides). Jelle Hellings. The 17th International Conference on Database Theory (ICDT 2014). 2014.
FoIKS 2014
Implication and Axiomatization of Functional Constraints on Patterns with an Application to the RDF Data Model (paper, local version, slides). Jelle Hellings, Marc Gyssens, Jan Paredaens, Yuqing Wu. Eighth International Symposium on Foundations of Information and Knowledge Systems (FoIKS 2014). 2014. (see also: AMAI 2015).
ICDT 2013
Walk Logic as a framework for path query languages on graph databases (paper, local version, slides). Jelle Hellings, Bart Kuijpers, Jan Van den Bussche, Xiaowang Zhang. The 16th International Conference on Database Theory (ICDT 2013). 2013.
SIGMOD 2012
Efficient external-memory bisimulation on DAGs (paper, local version, slides, poster, arXiv.org version, project page). Jelle Hellings, George H. L. Fletcher, Herman Haverkort. ACM SIGMOD International Conference on Management of Data (SIGMOD 2012). 2012. (see also: DBDBD 2011 and Master Thesis).

Talks

DBDBD 2016
Graph query optimization using semi-join rewritings (abstract, slides). Jelle Hellings. DBDBD 2016.
WOG 2013
Path Querying on Graph Databases (slides, abstract, short abstract). Jelle Hellings. WOG 2013.
DBDBD 2011
Efficient external-memory bisimulation on DAGs (abstract, slides, project page). Jelle Hellings. DBDBD 2011. (see also: SIGMOD 2012 and Master Thesis).

Others

Master Thesis
Bisimulation partitioning and partition maintenance (report, local version, midterm presentation slides, final presentation slides, project page, poster). Jelle Hellings under supervision of George H. L. Fletcher. Eindhoven University of Technology (TU/e). (see also: SIGMOD 2012 and DBDBD 2011).