Jena available via Maven

Jena is available as Maven artifacts. The Jena repository for released versions is http://jena.hpl.hp.com/repo and this is synchronized with the central Maven2 repository as http://repo1.maven.org/maven2/com/hp/hpl/. The artifacts include Jena and ARQ jar files, the Jena IRI library and associated software used by Jena which is distributed in source form.

Jena 2.5.5 and ARQ 2.2

There are new releases of Jena and ARQ:

• Jena-2.5.5 download
• ARQ 2.2 download

The versions of ARQ in the Jena download and version of Jena in the ARQ download are sync'ed to these releases. You only need download one of them to get the jars for both new versions. The different downloads contain different additional material such as source code.

SDB 1.0

SDB is a SPARQL database subsystem for Jena. It provides for large scale storage and query of RDF datasets using conventional SQL databases. The database tools for load balancing, security, clustering, backup and administration can all be used to manage the installation.

Supported databases:

• Oracle, 10gR2 & 11g including Oracle Express
• IBM DB2 9 including DB Express
• Microsoft SQL Server 2005 including SQL Server Express
• PostgreSQL v8
• MySQL 5.0 (>=5.0.22)
• HSQLDB 1.8
• Apache Derby 10.2

Download: http://downloads.sourceforge.net/jena/sdb-1.0.zip

Homepage:http://jena.sf.net/SDB

Documentation: http://jena.hpl.hp.com/wiki/SDB

We are actively seeking feedback on SDB - both good and bad. If it works, please tell us - if it doesn't work, please tell us!

Jena 2.5.4 and ARQ 2.1

There are new releases of Jena and ARQ:

• Jena-2.5.4 download
• ARQ 2.1 download

This is a co-ordinated release because this version of Jena introduces some low-level features that work with ARQ query planning to optimize the performance of large in-memory graph query.

The versions of ARQ in the Jena download and version of Jena in the ARQ download are sync'ed to these releases. You only need download one of them to get both new versions.

Also new in ARQ 2.1, as SPARQL extensions:

• GROUP BY and Counting
• The SERVICE keyword - call-out to another query service

ARQ 2.1 beta

The main feature of this release is the introduction of a cost-based optimizer for in-memory basic graph patterns. For queries that involve a large amount of searching of possibilities, the optimizer can greatly improve execution times by choosing the best order in which to execute the triple patterns in a basic graph pattern. The estimation is based on statistics that the underlying store has gathered but the framework also provides for the statistics gathered by studying the dataset itself to produce more detailed statistics. The optimizer is developed by Markus Stocker.

Jena tutorial on DevX

DevX have published an introductory tutorial on Jena's Model abstraction.

del.icio.us: jena, programming, semantic-web, tutorial

Jena User Conference: call for participation

Registration is open for the 2007 Jena User Conference. Early registration actually closes today, but normal registration remains open for a few more weeks yet. Please note the deadline of August 1st for all registrations, which we need in order that we can give firm numbers to the hosting venue.