Tyrex | Project

photo

Damien Graux

Since January 2016:
  Postdoctoral Researcher in Tyrex Team (Inria, France).

Prior Position:
  PhD. Student from November 2013 to December 2016 in Tyrex Team (Inria, France).
  Advisors: Nabil Layaïda and Pierre Genevès. Funded by: the Datalyse project.
  Defended on December 15, 2016. [Dissertation & Slides]. ☺

Research activities

Currently, I'm pushing further what I developed during my PhD thesis by integrating SPARQL evaluators into larger systems where various kinds of data structures are involved: several query results are needed (and aggregated) to build a complex answer. More specifically, I'm trying to design efficient languages to facilitate the development of optimized ETL pipelines in a semantic context.


During my PhD thesis, I focused on Semantic Web standards, especially on the Resource Description Framework RDF and its dedicated query language SPARQL. My main goal was to design efficient tools to evaluate SPARQL queries on very large RDF datasets (i.e. ≥100GB). Indeed, I provided a new reading grid to rank SPARQL evaluators before designing several efficient ones. More particularly, I worked on:

  • Distributed systems e.g. Apache Hadoop, Apache Spark...
  • RDF storage methods
  • SPARQL evaluation strategies in a distributed context
  • RDF/SPARQL Benchmarks

As a past time during my PhD main researches, I also designed a semantic pipeline for trip planning aggregating heterogeneous datasets (e.g. GTFS, RDF, CSV) in order to provide users touristic alternatives at plane stopovers.


Previously (before 2013), I worked on designing and implementing broadcast algorithms with special properties such as UTO (uniform and totally ordered). This work, mainly developed in C, is also openly available from github. [here].

Publications

(List generated from hal.inria.fr.)

  • [PRE-PRINT] HAP: Building Pipelines with Heterogeneous Data and Hive [HAL, PDF, Abstract]

    Damien Graux, Pierre Genevès, Nabil Layaïda
    2017
  • [PHD] On the Efficient Distributed Evaluation of SPARQL Queries [HAL, PDF, Abstract]

    Damien Graux
    Web. Université Grenoble Alpes, 2016. English
  • [CONFERENCE] SPARQLGX : Une Solution Distribuée pour RDF Traduisant SPARQL vers Spark [HAL, PDF, Abstract]

    Damien Graux, Louis Jachiet, Pierre Genevès, Nabil Layaïda
    BDA 2016 - 32ème Conférence sur la Gestion de Données - Principes, Technologies et Applications, Nov 2016, Poitiers, France. BDA2016
  • [CONFERENCE] SPARQLGX: Efficient Distributed Evaluation of SPARQL with Apache Spark [HAL, PDF, Abstract]

    Damien Graux, Louis Jachiet, Pierre Genevès, Nabil Layaïda
    The 15th International Semantic Web Conference, Oct 2016, Kobe, Japan. The 15th International Semantic Web Conference, <10.1007/978-3-319-46547-0_9>
  • [CONFERENCE] Smart Trip Alternatives for the Curious [HAL, Abstract]

    Damien Graux, Pierre Genevès, Nabil Layaïda
    15th International Semantic Web Conference (ISWC 2016 demo paper), Oct 2016, Kobe, Japan. 15th International Semantic Web Conference
  • [CONFERENCE] SPARQLGX in Action: Efficient Distributed Evaluation of SPARQL with Apache Spark [HAL, PDF, Abstract]

    Damien Graux, Louis Jachiet, Pierre Genevès, Nabil Layaïda
    15th International Semantic Web Conference (ISWC 2016 demo paper), Oct 2016, Kobe, Japan. 15th International Semantic Web Conference
  • [PRE-PRINT] A Multi-Criteria Experimental Ranking of Distributed SPARQL Evaluators [HAL, PDF, Abstract]

    Damien Graux, Louis Jachiet, Pierre Genevès, Nabil Layaïda
    Submitted. 2016
  • [CONFERENCE] TRAINS : a Throughput-Efficient Uniform Total Order Broadcast Algorithm [HAL, Abstract]

    Michel Simatic, Arthur Foltz, Damien Graux, Nicolas Hascoet, Stéphanie Ouillon, Nathan Reboud, Tiezhen Wang
    NTDS - ICPE 2015 : International Conference on Protocol Engineering (ICPE) and International Conference on New Technologies of Distributed Systems (NTDS), Jul 2015, Paris, France. IEEE, Proceedings NTDS - ICPE 2015 : International Conference on Protocol Engineering (ICPE) and International Conference on New Technologies of Distributed Systems (NTDS), pp.1 - 8, 2015, <10.1109/NOTERE.2015.7293477>

Software

I also contributed to:

  • SPARQLGX: an efficient distributed evaluator of SPARQL queries based on Apache Spark.
  • RDFHive: a direct evaluator of SPARQL queries on top of Apache Hive.
  • SDE: a solution to directly evaluate SPARQL queries using Apache Spark.
  • GTFS-Store: the first distributed store dedicated to GTFS datasets which uses Apache Spark to find paths.

Teaching

Between September 2014 and June 2016 i.e. over two school years, I was a math interrogateur oral aka khôlleur at Lycée Champollion (Grenoble, France). I taught more than 70 hours to respectively MP and PC students i.e. relatively to the American education system, second year students of bachelor degrees in mathematics and in physics.

pdf An excerpt of given exercises (in French). [kholles.pdf]

Misc.

In parallel, I also try to find time to:

  1. Develop and update electronic projects that have been pending for several years such as:
    • a basic 8-bits game console created from scratch which only uses an ATmega168. [here]
    • a $2-less slide presenter which outputs slideshows on a simple video wire (like the yellow ones behind TVs) while using only one microcontrolor: in this case an ATmega168. [here]
  2. Finish (after all) the coinche book I'm writing. [The current (and unfinished) version of the book in French.]
  3. Smile and go out with friends...

Contact