Service Definition for SQL DB Services

Hi Folks,

I'm quite new to Dreamfactory and I have configured an Oracle XE database, which is working great btw, but I was wondering if I can create my own Services Definition based on this existing SQL DB service, by configuring the Services Definition Tab. I tried to do this, it updated the Service successfully, but nothing happens. It's not visible in the API Docs tab.
Is something that cannot be done?