98.You plan to execute the following command to perform a Flashback Database operation in your
database:
SQL> FLASHBACK DATABASE TO TIMESTAMP (SYSDATE -5/24);
Which two statements are true about this? (Choose two)
A. The database must have multiplexed redo log files
B. The database must be in the MOUNT state to execute the command
C. The database must be in the NOMOUNT state to execute the command
D. The database must be opened in RESTRICTED mode before this operation
E. The database must be opened with the RESETLOGS option after the flashback operation
Answer: BE


验证：
SQL> flashback database to timestamp (sysdate - 1);
flashback database to timestamp (sysdate - 1)
*
ERROR at line 1:
ORA-38757: Database must be mounted and not open to FLASHBACK.




SQL> shutdown immdiate
SP2-0717: illegal SHUTDOWN option
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount
ORACLE instance started.


Total System Global Area  413372416 bytes
Fixed Size                  2253784 bytes
Variable Size             314575912 bytes
Database Buffers           88080384 bytes
Redo Buffers                8462336 bytes
Database mounted.
SQL> flashback database to timestamp (sysdate - 1);


Flashback complete.


SQL> alter database open;
alter database open
*
ERROR at line 1:
ORA-01589: must use RESETLOGS or NORESETLOGS option for database open




SQL> alter database open resetlogs;
Database altered.