Originally posted by tamilselvan
To avoid those error.

1. Create larger rollback segments.
2. Set minimum extents to 20 and maxextents to 500 for each rollback segment.
3. Create more number of rollback segments.
Not 3! 1 is also a bit questionable. Let me explain why. Every 12th hour SMON tries to shrink the rollback segments. The rollback information related to the shrink is logged into the current rollback extent. This segment gets full at one stage. Then Oracle makes an attempt to wrap into the next extent. But it is the one being shrunk. Thus Ronnie gets the errors. Your 2nd advise should help.