Just to discuss, a question I've seen while studying:

What file or files must be restored if one datafile is lost or removed when the restored files are based on a cold backup?

1) The lost datafile and neccessary archive logs
2) All data files only
3) All data files and control files
4) All data files, control files and online redo logs


That question seemed very misleading for me. If the database is in ARCHIVELOG and the failure happened after the last cold backup the answer is (1). So, it is enough to restore the lost the datafile from the cold backup and recover it.

However, the "right" answer is (4), that makes sense if the database is in NOARCHIVELOG. That way, there is not recovery, just the last cold backup is restored and all the changes made between the backup and the failure are lost.

Very unclear, don't you think? If exams questions are like that (bad-written), it'll be pretty tough.

Please correct me if I'm wrong.