While trying to recreate undotbs to flip with a new one , ran into this unseen error.
Created a new UNDO, made it the default UNDO for the database, now while trying to drop the old undo it fails with error Ora-01548 .
Following steps were performed:
1. Figure out the rollback segments still occupying UNDOTBS1
2. Create pfile if you started with database with spfile.
3. Edit pfile and set undo management to manual.
4. Put the entries of the undo segments in the pfile by using the following statement in the pfile:
5. Mount the database using new pfile.
6. Drop the datafiles,
7. Open the database.
8. Drop the undo segments,
9. Drop Old undo tablespace.
10. Add the new undo tablespace.
11. Shutdown Immediate;
12. Change the pfile parameters back to Undo_management = AUTO and modify the parameter Undo_tablespace=new_undo_tablespace_name and remove the _offline_rollback_segments parameter.
13. Startup the Database.