Section: Software


Participants : Bruno Paiva Lima Da Silva, Jean-François Baget, Madalina Croitoru.

Alaska (http://alaska.bplsilva.com/ ) is a java library dedicated to the storage and querying of large knowledge bases. It intends to be the foundation layer of our OBDA (Ontology Based Data Access) software developments. It has been built, first as part of a Master's thesis, and now of the PhD of Bruno Paiva Lima da Silva [34] .

In Alaska, facts and queries are defined via a generic interface that favors a logical view of these objects. Implementations of this interface allow for the storage of facts w.r.t. different storage paradigms and systems (e.g., relational databases MySQL and Sqlite; triple stores Sesame and graph databases Neo4J, DEX, HyperGraphDB and OrientDB). For the time being, we can store 10 7 to 10 8 atoms. In the same way, logical queries can be evaluated through different methods, be it the native querying mechanism of the database used (e.g. SPARQL or SQL), or specifically designed algorithms (from a simple backtrack to a full constraint solver based upon Choco for hard problem instances). Note that all these methods provide the same answer set to queries.

This library already allows for testing our OBDA algorithms on large instances (it is already used by other PhD students for their experiments), and will soon be ready to be distributed to a broader audience. Our generic approach will ease this dissemination to different research domains.