QUESTION 32
To accomplish user-managed backup for the USERS tablespace, you issued the following command to put the
database in backup mode:
SQL> ALTER TABLESPACE users BEGIN BACKUP;
While copying the file to the backup destination a power outage caused the instance to terminate abnormally.
Which statement is true about the next database startup and the USERS tablespace?
A. The database will open, and the tablespace automatically comes out of the backup mode.
B. The database will be mounted, and recovery must be performed on the USERS tablespace.
C. The database will be mounted, and data files in the USERS tablespace must be taken out of the backup mode.
D. The database will not be mounted, and you must restore all the data files for the USERS tablespace from the backup, and perform recovery.
Answer: C
同611题：http://blog.csdn.net/rlhua/article/details/18821889
Explanation/Reference:
Section: Backup, Recovery & Recovery Manager (RMAN)
http://www.informit.com/articles/article.aspx?p=30348
Database Crashes During Hot Backup
There can be many reasons for the database to crash during a hot backup-a power outage or rebooting of the
server, for example. If these were to happen during a hot backup, chances are that tablespace would be left in
backup mode. In that case you must manually recover the files involved, and the recovery operation would end
the backup of tablespace. It's important to check the status of the files as soon as you restart the instance and
end the backup for the tablespace if it's in backup mode.
select a.name,b.status from v$datafile a, v$backup b where a.file#=b.file# and b.status='ACTIVE';
or
select a.tablespace_name,a.file_name,b.status from dba_data_files a,v$backup b where a.file_id=b.file# and b.status='ACTIVE';
This statement lists files with ACTIVE status. If the file is in ACTIVE state, the corresponding tablespace is in
backup mode. The second statement gives the tablespace name also, but this can't be used unless the
database is open. You need to end the backup mode ofthe tablespace with the following command:
alter tablespace tablespace_name end backup;