Here's a scenario that's a problem with the Oracle Database Backup Service (ODBS). This isn't a rant against Oracle - rather I'm just illustrating a possible configuration or sequence of events with the ODBS that could cause a serious issue given the current restrictions of the ODBS.
Months ago I created a database, backed it up to the Oracle Database Backup Service via the OPC RMAN module, deleted all backups, and removed the database. Now months later I notice that the Oracle Database Backup Service still shows 12MB of storage being used. Now I thought that I had properly deleted all of the backup files on the ODBS through RMAN. At least RMAN didn't list any backups. But something must still be there.
And that's the problem: The Oracle Database Backup Service provides me no way of seeing what's using up the 12MB. I can't see the backup piece or file name. And similarly I can't delete it. I contacted Oracle who said that I need to manipulate the files through RMAN. But again, I can't catalog a SBT_TAPE backup piece so I can then delete it without knowing the piece name. Hence I'm stuck. Data backed up to the ODBS doesn't show in the Oracle Storage Cloud Service at all so I can't view or manipulate the file(s) there either.
And another interesting anomaly: last Tuesday it shows the space usage as dipping down from ~12MB to ~10.5MB. Then last Wednesday it's back up to the ~12MB. I'm clearly not accessing this file(s) so this also shows that Oracle's ability to monitor the space used is suspect.
Contacted the Oracle Cloud help who said that since I have a trial account I convert into a paid account so they could investigate the issue. But sorry, that's not a very good trial as they're essentially saying to me "try our products for free and if they don't work, then pay us with a paid account and we'll look at why it doesn't work for you". I equate it to "test drive this new car and if you can't work out how to turn on the air conditioning, just buy the car and then our mechanics will help you". On that argument they said they would look into it and email me back but I'm yet to hear anything.
If this was an AWS S3 backup using Oracle Secure Backup I could still access the bucket via the AWS management console where I could see the RMAN backup piece name so I could catalog it with RMAN or just delete it right there from the AWS console. But with the Oracle Database Backup Service there's no such option to view the details or manually delete the content so I'm stuck with the data.
Seems like how they've tightened down access to the ODBS storage through RMAN interfaces only poses some pretty serious problems. It's certainly possible that a DBA backs up a database to this service, and decommissions the database prior to removing all of the ODBS backup data only to later discover that it's now orphaned.