Migrate Oracle 12c to 18c in AWS RDS Currently we have an Amazon RDS Oracle 12c instance and we need to upgrade it to Oracle 18c in a new RDS instance.

What is the correct approach to do this?

Can we set up an 18c instance staright away and then restore a 12c snapshot or do we need to Set up a new 12c instance and restore a snaphot and then upgrade to 18c?
Can we use AWS DMS to migrate from RDS 12c to RDS 18c?
I was able to do this and it was a very smooth process at the end.

Just took a snapshot of the current 12c RDS instance and restore it. Restoration creates a new 12c RDS instance, but have to be careful about the instance type.

After all I upgraded it to 18c with a one click as they say in the documents. 

The schema, users, passwords were all there in the new RDS as the old one. Did not require any kind of Oracle administrator skill.