多选题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?（）AThe database must have multiplexed redo log filesBTh

第1题：

You are working on an Oracle Database 10g database. You enabled the Flashback Database feature. Which two statements regarding flashback logs are true？ （）

• A、 Flashback logs are not archived.
• B、 Flashback logs are maintained in redo log files.
• C、 Flashback logs are maintained in the Flash Recovery Area.
• D、 Flashback logs are used to maintain Flashback Database related errors.
• E、 Flashback logs need to be cleared manually after you disable Flashback Database.

第2题：

You are working on an Oracle Database 10g database. Because of data loss， you decided to perform a Flashback Database operation using the following command：  SQL> FLASHBACK DATABASE TO TIMESTAMP（SYSDATE 5/24）;  Which two statements are true？ （）

• A、SYSDATE should not be used with TIMESTAMP.
• B、The database must have multiplexed redo log files.
• C、The database must be in the MOUNT state to execute the command.
• D、The database must be opened with the RESETLOGS option after the flashback operation.
• E、The entire database needs to be restored from the most recent backup before the flashback operation.

第3题：

第4题：

These are the details about V$FLASHBACK_DATABASE_STAT：  SQL> DESC V$FLASHBACK_DATABASE_STAT Name Null？ Type  ------------- -------- --------------  BEGIN_TIME DATE END_TIME DATE  FLASHBACK_DATA NUMBER  DB_DATA NUMBER REDO_DATA NUMBER  ESTIMATED_FLASHBACK_SIZE NUMBER  Which two statements regarding the V$FLASHBACK_DATABASE_STAT view are true？ （）

• A、BEGIN_TIME is the time at which Flashback logging is enabled.
• B、END_TIME is the time at which the query is executed on the view.
• C、REDO_DATA is the number of bytes of redo data written during the interval.
• D、This view contains information about flashback data pertaining to the last 24 hours.
• E、FLASHBACK_DATA is the amount of flashback data generated since the database was opened.

第5题：

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？（）

• 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

第6题：

You are maintaining a database that is in ARCHIVELOG mode. You have configured the flash recovery area in your database. The database is in MOUNT EXCLUSIVE mode， and you want to configure the Flashback Database feature. Which two options are NOT required to configure the Flashback Database feature？ （）

• A、 Open the database in read-only mode.
• B、 Set the retention target with the DB_FLASHBACK_RETENTION_TARGET initialization parameter.
• C、 Enable the block change tracking feature.
• D、 Execute the ALTER DATABASE FLASHBACK ON statement.

第7题：

Which two statements are true regarding the database in ARCHIVELOG mode？（）

• A、You have to shut down the database to perform the backups.
• B、Archiving information is written to the data files and redo log files.
• C、You can perform complete database backups without closing the database.
• D、Online redo log files have to be multiplexed before putting the database in ARCHIVELOG mode.
• E、All the previous database backups become invalid after you configure the database to ARCHIVELOG mode.

第8题：

第9题：

After performing a clean shut down of the database instance for maintenance， you mount the database andthen execute a command to open the database：SQL> ALTER DATABASE OPEN； Which two statements are true（）

• A、The online redo log files and online data files are opened.
• B、All the online data file headers are checked for consistency.
• C、Instance recovery is performed before opening the database.
• D、The path and existence of all the log file members are checked

第10题：

Which three statements are true about Flashback Database?（）

• A、Flashback logs are written sequentially, and are archived.
• B、Flashback Database uses a restored control file to recover a database.
• C、The Oracle database automatically creates, deletes, and resides flashback logs in the Fast Recovery Area.
• D、Flashback Database can recover a database to the state that it was in before a reset logs operation.
• E、Flashback Database can recover a data file that was dropped during the span of time of the flashback.
• F、Flashback logs are used to restore to the blocks' before images, and then the redo data may be used to roll forward to the desired flashback time.