How long does a rollback take to be done? I tried to delete 42 million records in a table and waited for three hours. After that I had to kill the script to do a truncate. But I am still getting ORA-00054.
A rollback can take quite a long time to complete. I would guess that by the time you get this answer, your rollback will have completed.
But for future reference, a rollback operation can be a lengthy one, especially if you are rolling back a 42 million row delete operation.
Obviously, the further along you are in the DELETE operation, the longer the rollback will take. However, the actual amount of time may vary due to many different factors. You may have to compete for resources from other processes. Those resources can include CPU and disk I/O.