How to connect to a database using xproc

Hi,

I'm wondering what is involved in connecting to a database and executing a
query using xproc. I came across the following:


   1. User defined xquery connection to existDB
   1. http://code.google.com/p/bpel-workflow/
   2. A shared a library to manage eXist *databases*
   1. http://bitbucket.org/jasulak/exist-xproc-library/wiki/Home


My client is interested to connect to the derby database.

Any general thoughts are welcome as I'm not certain where to start exactly.

Regards

Alex

-----
The Bafiila Acoustic Trio makes easy to listen to relaxing music which
blends Western and West African influences.
http://www.facebook.com/home.php?#!/pages/Bafila-Acoustic-Trio/125611807494851