Database Technologies
for Semantic Web
Edilson Ribeiro da Silva Júnior
José Maria Silveira Neto

TripleStore
 triple {subject, predicate, object}
 TripleStore is an RDF Database.
 add(triple), remove(triple), triples(pattern), ...

Sesame
 An open­source framework for querying,
inferencing and analyzing RDF data.
 SeSQL
 BSD­style license
 Java
 PostgreSQL, MySQL, Microsoft SQL Server and
Oracle databases.

SeSQL
 Sesame RDF Query Languag, ”circle”
 is a new RDF/RDFS query language that is currently
being developed by Aduna as part of Sesame. It
combines the best features of other (query)
languages (RQL, RDQL, N­Triples, N3) and adds
some of its own.
 Graph transformation, RDF Schema support, XML
Schema datatype support, Expressive path
expression syntax, Optional path matching.

Virtuoso
 object­relational SQL database
 built­in web server
 SPARQL
 GPLv2
 ODBC, JDBC, ADO .Net and OLE/DB.
 C, Java, etc.

Jena
 HP Labs Semantic Web Programme
 RDF API
 Reading and writing RDF in RDF/XML, N3 and N­
Triples
 OWL API
 In­memory and persistent storage
 SPARQL query engine
 Jena SDB
 BSD­style license

R2RQ
 D2RQ is a declarative language to describe
mappings between relational database schemata and
OWL/RDFS ontologies. The D2RQ Platform uses
these mapping to enables applications to access a
RDF­view on a non­RDF database through the Jena
and Sesame APIs, as well as over the Web via the
SPARQL Protocol and as Linked Data.

Large TripleStores
 Garlik JXT (9.8B)  Jena with PostgreSQL (200M)
 YARS2 (7B)  Kowari (160M)
 BigOWLIM (1.85B)  3store with MySQL 3 (100M)
 Virtuoso Open­Source Edition  Sesame (70M)
(1B+)
 AllegroGraph (1B)
 Jena SDB (650M)
 Mulgara (500M)
 RDF gateway (262M)

References
 http://rdflib.net/2005/10/26/rdflib­2.2.4/doc/triple_store.
 http://en.wikipedia.org/wiki/Triplestore
 http://recuperaciondeinformacion.itrello.com/SeRQL­en
 http://esw.w3.org/topic/LargeTripleStores
 http://www4.wiwiss.fu­berlin.de/bizer/D2RQ/