Oracle Solution for Error ora-01581

ORA-01581: attempt to use rollback segment (string) new extent (string) which is being allocated

What triggered the Error:

Undo generated to extend a rollback segment run out of current undo block space and is attempting to write into the new extent which has not been completely allocated.

What should we do to fix it:

The rollback segment extending will be rollbacked by the system, no more extension will be possible untill the next extent is freed up by rolling back or committing other transactions.