Comment 19 for bug 309626

To enable sesame2, you may need to help it find the Sun java libraries. You can check if sesame2 works by running sopranocmd: it lists the available backends. Add the line

/usr/lib/jvm/java-6-sun/jre/lib/i386/server

to /etc/ld.so.conf and run 'sudo ldconfig'. After that sesame2 should be listed in addition to redland. Now you can edit ~/.kde/share/config/nepomukserverrc as jiveaxe suggests.

I read somewhere that if you use openjdk, installing the whole sdk package may help to get sesame working.