OCP-1Z0-053-V12.02-98题

 

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

答案解析：

参考：http://docs.oracle.com/cd/E11882_01/server.112/e41084/statements_9011.htm#SQLRF01801

• TO TIMESTAMP reverts the database back to its state at the specified timestamp.

Purpose

Use the FLASHBACK DATABASE statement to return the database to a past time or system change number (SCN). This statement provides a fast alternative to performing incomplete database recovery.

Following a FLASHBACK DATABASE operation, in order to have write access to the flashed back database, you must reopen it with an ALTER DATABASE OPEN RESETLOGS statement.

Prerequisites

You must have the SYSDBA system privilege. A fast recovery area must have been prepared for the database. The database must have been put in FLASHBACKmode with an ALTER DATABASE FLASHBACK ON statement unless you are flashing the database back to a guaranteed restore point. The database must be mounted but not open. In addition:

• The database must run in ARCHIVELOG mode.

• The database must be mounted, but not open, with a current control file. The control file cannot be a backup or re-created. When the database control file is restored from backup or re-created, all existing flashback log information is discarded.

• The database must contain no online tablespaces for which flashback functionality was disabled with the SQL statement ALTER TABLESPACE ... FLASHBACKOFF.