First I got the ORA-01578 data block corrupted on file #3, block #4159 error message. Then, I found out that corruption is on the rollback segment RB3. I took the RB3 offline. I tried to remove it and recreate it again. But, I got another ORA-01545 rollback segment 'RB3' specified not available. Yes, it was pending offline not offline. Please advice!