Easiest option would be to check whether your DB supports JDBC - some NoSQL DBs support subset of functionality through JDBC and sometimes it is enough. They you can try to use it with Clover. Some JDBC drivers works even if they are officially unsupported.
If you decide to write your own component I have some links for you:
* http://doc.cloveretl.com/documentation/ ... index.html
* Sources of DbInputTable and MongoDb* are available for download on SourceForge http://sourceforge.net/projects/cloveretl/
as part of OpenSource Engine so you can take a look on it
* JavaDoc is also available on SourceForge
We typically base our decision on particular DB support on customer requests. Can you please tell me what database you are interested in? It would help us. Thank you!