The database Is configured in ARCHIVELOG mode. The database needs to be up 24 X 7. You want to perform
user managed backup for the data files of the HR_DATA tablespace. To accomplish the task, you issued the
following command:
SQL> ALTER TABLESPACE hr_data BEGIN BACKUP;
Which two statements are true in this scenario? (Choose two.)
A.
No transaction on the tablespace is allowed but you can perform queries.
B.
The tablespace will automatically come out of backup mode when the file copy is complete.
C.
The checkpoint change number is frozen in headers of the data files until the file is removed from backup
mode.
D.
The database writes the before image of an entire block to the redo stream before modifying. block tor the
first time.
Explanation:
Making User-Managed Backups of Online Read/Write Tablespaces
You must put a read/write tablespace in backup mode to make user-managed data file backups when the
tablespace is online and the database is open. The ALTER TABLESPACE … BEGIN BACKUP statement
places a tablespace in backup mode. In backup mode, the database copies whole changed data blocks into the
redo stream. After you take the tablespace out of backup mode with the ALTER TABLESPACE … ENDBACKUP or ALTER DATABASE END BACKUP statement, the database advances the data file checkpoint
SCN to the current database checkpoint SCN.
When restoring a data file backed up in this way, the database asks for the appropriate set of redo log files to
apply if recovery is needed. The redo logs contain all changes required to recover the data files and make them
consistent.