How to fix the Oracle error ORA-30018: Create Rollback Segment failed, USN string is out of range?

In this post, you’ll learn more about the Oracle ErrorORA-30018: Create Rollback Segment failed, USN string is out of range with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-30018: Create Rollback Segment failed, USN string is out of range

Reason for the Error ORA-30018: Create Rollback Segment failed, USN string is out of range

the system runs out of undo segment number. Too many undo segments exist.

How to fix the Error ORA-30018: Create Rollback Segment failed, USN string is out of range ?

You can fix this error in Oracle by following the below steps

drop some of the unused undo segments and retry operation.