Alter Database Open Resetlogs Upgrade

Had to restore a database to a point-in-time from a hotbackup.  Followed Steps:

1. Copied datafiles to target
2. Created a New Controlfile
3. Recovered using syntax: RECOVER DATABASE UNTIL TIME 'YYYY-MM-DD:HH:MI' USING BACKUP CONTROLFILE;
4. Ran ALTER DATABASE OPEN RESETLOGS;

... and that's when the wheels fell off, with the database instance terminated and errors in the alert log advising startup upgrade needs to be done.

The reason for this is that the target database was upgraded sometime after the point in time recovery date.

In the past, when faced with this situation, I was able to point the database and the /etc/oratab entries to the old Oracle Home and recover that way, but in this instance the old home had been removed and well a more elegant solution needed to be found.

Resolution:

1. Copied datafiles to target
2. Created a New Controlfile
3. Recovered using syntax: RECOVER DATABASE UNTIL TIME 'YYYY-MM-DD:HH:MI' USING BACKUP CONTROLFILE;
4. Ran ALTER DATABASE OPEN RESETLOGS UPGRADE;

The next step is to then apply the upgrade scripts and breathe a sigh of relief!