ORA-00283 and ORA-00264
When you saw both ORA-00283 and ORA-00264 at the same time like the following:
SQL> recover database;
ORA-00283: recovery session canceled due to errors
ORA-00264: no recovery required
Don't worry about it, it means that the controlfile and data files have been consistent, no recovery is required to open the database.
Usually, it's because: