649.Examine the CREATE DISKGROUP command used to create a disk group: SQL> CREATE DISKGROUP misc EXTERNAL REDUNDANCY DISK 'ORCL: FRA3' NAME misc1, 'ORCL: FRA4' NAME misc2; In which situation would you use this method of disk group creation?
A.When two-way disk mirroring is required for the allocation units
B.When three-way disk mirroring is required for the allocation units
C.When using hardware mirroring or RAID
D.When disk mirroring is required for the Automatic Storage Management (ASM) disks
正确答案是C