When you create an autonomous database, the database (host & port number) is easily accessible from anywhere in the world (Though you would additionally need username and password and SSH keys)
But with new features now you can restrict everyone and allow only a few selective IPs who can access that database.
Check my post here: https://k21academy.com/clouddba44
Where I’ve covered all like:
✔ Access Control List in Autonomous Database
✔ New Feature Updates
✔ Steps To Restrict Access To Your autonomous Database Using ACL, and much more…
Oracle ACE, Author, Speaker and Founder of K21 Technologies & K21 Academy : Specialising in Design, Implement, and Trainings.