Which are the correct steps, in order, to deal with the loss of an online redo log if the
database has not yet crashed?
a: Issue a checkpoint.
b: Shut down the database.
c: Issue an alter database open command to open the database.
d: Startup mount the database.
e: Issue an alter database clear logfile command.
f: Recover all database datafiles.
A.
a, b, c, d
B.
b, d, e, c
C.
a, b, d, e, c
D.
b, f, d, f, c
E.
b, d, a, c
why C .. do i have to do checkpoint
If you lose an Online Redo Log, you may lose the CVs stored in the Online Redo you lost, but with Checkpoint you update Datafiles!
Forcing a checkpoint ensures that all changes to the database buffers are written to the data files on disk.