|| Either: 1) Make the rollback segment available; for example, bring an offline tablespace online. 2) Remove the name from the ROLLBACK_SEGMENTS parameter if the name is a duplicate or if another instance has already acquired the rollback segment. 3) Bring the rollback segment offline first. This may involve waiting for the active transactions to finish, or, if the rollback segment needs recovery, discover which errors are holding up the rolling back of the transactions and take appropriate actions. 4) Same as 3). 5) Remove the name from the _corrupted_rollback_segments parameter.