In order to consume the data from the external oracle db, you will first create a federated data class. Like you mentioned, the underlying form created for this Federated class is an AR Vendor form.
So, once it is in place, you will be able to use it just like any other AR form. You will be able to query it, you can attach workflows to push data into other forms, etc.
The part about being able to see it in atrium explorer, is basically telling you you can create association between CDM class and this Federated data class through Federated relationship. once you establish a relationship, you could see the connection between your CDM CI and the CI from the federated data (just like how you can see a computer system is associated with a disk, for example).
Can you also managed them as is they are inside CMDB, for example relat
ing the to an incident? How?
I created a detailed new thead on this argument
where is the thread /?