Section: New Software and Platforms

Graal

Participants : Clément Sipieter, Jean-François Baget, Marie-Laure Mugnier, Swan Rocher.

Graal is a new software platform written in java, built since March 2014 from the Alaska platform developed during Bruno Paiva Lima Da Silva's PhD thesis. It also integrates algorithms developed by various members of the team. It is developed by Clément Sipieter thanks to the Inria ADT QUASAR.

Graal is intended to be a generic platform for ontological query answering with existential rules. It will implement and allow to compare various paradigms that fall into that framework.

In its current state, Graal allows storage of data via a generic interface in different storage paradigms and systems. Currently, the relational database management systems MySQL, PostgreSQL, Sqlite, and InMemory graph and LinkedList structures are implemented. The triple store Jena TDB and the graph database system Sparksee are coming soon. Graal also allows us to query this database taking into account an ontology represented by a set of existential rules. It provides forward chaining and backward chaining algorithms (building up on the work of Mélanie König) and a tool for the analysis of the properties of a set of rules which is an integration of Swan Rocher's tool Kiabora http://www2.lirmm.fr/~mugnier/graphik/kiabora/ . The input and output of this software can be expressed in our Datalog-inspired format DLGP or in the Semantic Web language OWL. This software is designed in a modular way, hence it is possible to use only a subpart of Graal without embedding it all or to easily replace an implementation of a module by another.