[DL] -ontop- v1.7-alpha b1692 is now available

[Mariano Rodriguez]

We are happy to announce the availability of a new build of version
-ontop- 1.7-alpha, a Java framework for Ontology Based Data Access
(OBDA). Using -ontop- it is possible to query very large RDBMS
through the vocabulary and semantics of RDFS/OWL 2 QL ontologies
using SPARQL.

SPARQL query answering in -ontop- is done by means of SPARQL-to-SQL
translations. The SQL query generated by -ontop- is executed directly
at the DBMS, with no data moving back and forth. Moreover, the system
uses a variety of techniques (e.g., query rewriting, partial
evaluation, query containment, SQL analysis, virtual RDF graph
completion) to generate minimal and 'lean' SQL queries
that can be planned and executed efficiently by open source and
commercial DBMS alike. 

The functionality of -ontop- is similar to that offered by systems
like 'D2RQ server', 'SquirrelRDF' and 'Virtuoso RDF views', however
the techniques used in -ontop- provide much better performance in
several use cases (the best reported case has been up 500x times
faster than Virtuoso RDF views).

The -ontop- framework includes:
  * -ontopPro- A Plugin for Protege 4.x that allows to create
    mappings for your OWL 2 QL/RDFS ontologies.
  * QuestOWL A SPARQL engine implemented in Java and compatible with 
    the OWLAPI 3 that provides efficient query answering and 
    supports RDFS and OWL 2 QL entailments.

The framework is still in alpha and has several rough edges, however,
given the performance it is currently able to deliver we think it
might be interesting to give it a test drive. The system is available
at 

      http://obda.inf.unibz.it/protege-plugin/index.html

The -ontop- development team