Choose two.
When backing up to the Oracle Fast Recovery Area (FRA) you determine that the backup takes too long and suspect a performance bottleneck.
Which two are true about diagnosing and tuning these problems?
A.Data files with a high value in V$BACKUP_ASYNC_IO.SHORT_WAITS are a potential performance bottleneck when asynchronous I/O is used. B.If an RMAN BACKUP VALIDATE command takes roughly the same time as an actual backup then read I/O is a likely bottleneck. C.If an RMAN BACKUP VALIDATE command takes noticeably less time than an actual backup then write I/O is a likely bottleneck. D.Ifan RMAN BACKUP VALIDATE command takes roughly the same time as an actual backup then both read and write I/O are likely bottlenecks. E.Data files with a high value in V$BACKUP_SYNC_IO.DISCRETE_BYTES_PER_SECOND are a potential performance bottleneck when synchronous I/O is used.正确答案BC
