RDB is the original subsystem to persist RDF and OWL data. It is deprecated 
for new development. Documentation on RDB is available on-line:

 - RDB - http://openjena.org/DB/

There are two other subsystems for persisting RDF and OWL data, SDB or TDB. 
These are separate downloads:

 - SDB documentation - http://openjena.org/SDB/
 - TDB documentation - http://openjena.org/TDB/

This module uses Maven to manage compilation, packaging, release and testing. 
There are multiple profiles for different databases. By default HSQLDB is
used, but it's possible to change profile using -P option, for example:

  mvn test -P derby
  mvn test -P mysql
  mvn test -P postgresql
  mvn test -P hsqldb,hsqldb-mem
  
Use mvn help:all-profiles to list all the available profiles.

To generate the Eclipse files use:

  mvn eclipse:clean eclipse:eclipse -DdownloadSources=true -DdownloadJavadocs=true


                                                      The Jena team