1z0-043章節(jié)練習(2019.04.28)

View the Exhibit. 

You executed the following command to perform a backup of the USERS tablespace： 
RMAN> BACKUP 
TABLESPACE USERS; 
Which three types of files are backed up？ （）

In your datawarehousing application， you generate reports frequently. The data is static in the tables being used to generate reports. You are currently using joins， resulting in a large performance overhead. 
What kind of database structure would you use to reduce the response time of the query？（） 

You execute the following command to perform a backup by using Recovery Manager （RMAN）： RMAN> run 
{allocate channel c1 type sbt; 
backup datafile 1; 
} 
The command errors out. A part of the error message is as follows： 
RMAN­03009： failure of allocate command on c1 channel 
ORA­19554： error allocating device， device type： SBT_TAPE， device name： 
What could explain why the statement failed？（）