A. If an RMAN BACKUP VALIDATE command takesroughly the same time as an actual backup, then both read and write I/O are likely bottlenecks.

B. Setting DBWR_IO_SLAVES to a non zero value can improve backup performance when using synchronous I/O.

C. If an RMAN BACKUP VALIDATE command takes noticeably lessthan an actual backup, then write I/O is a likely bottleneck.

D. If an RMAN BACKUP VALIDATE command takesroughly the same time as an actual backup, then read I/O is a likely bottleneck.

E. Data files with a high value in V$BACKUP_SYNC_IO.DISCRETE_BYTES_PER_SECOND are a potential performance bottleneck when synchronous I/O is used.

F. Setting DBWR_IO_SLAVES to a non zero value can improve backup performance when using asynchronous I/O/

G. Data files with a high value in V$BACKUP_ASYNC_IO.SHORT_WAITS are a potential performance bottleneck when asynchronous I/O is used.