053-545

When performing an online backup, what is the proper order of the following steps?
A. Issue the alter database end backup command.
B. Back up the archived redo logs.
C. Issue the alter database begin backup command.
D. Back up the database files.
E. Determine the beginning log sequence number.
F. Determine the ending log sequence number.
G. Force a log switch with the alter system switch logfile command.
A. a, b, c, d, e, f, g
B. c, d, a, b, e, g, f
C. f, d, b, g, a, c, e
D. e, c, d, a, g, f, b
E. a, f, b, g, e, c, d

　　First you determine the beginning log sequence number,then you issue the alter database begin backup command,then you back up the database files,and then you issue the alter database end backup command.Next you force a log switch the alter system switch logfile command,and then you determine the ending log dequence number.Finally,you backup the archived redo logs.