多选题You are working on a test database where instance recovery takes a considerable amount of time. How can reduce the recovery time？（）ABy multiplexing the control filesBBy multiplexing the redo log filesCBy decreasing the size of redo log filesDBy configu

第1题：

Which statement is true regarding the Archiver （ARCn） process，archived log files，and recovery？ （）

• A、A database backup, combined with archived redo log files, guarantees that all committed data can be recovered to the point of failure. 
• B、During recovery the ARCn background process copies its redo entries identified for recovery by the control file to the data files. 
• C、After each write to an archived log, the mandatory background process ARCn writes its log sequence number and the first and last SCN number within the log sequence to the control file. 
• D、At database recover time, and archived redo log is uniquely identified for recovery use by its redo thread number and destination ID number retrieved from the control file.

第2题：

In which two cases would you perform only consistent backup？（）

• A、You are working on a database where downtime is not tolerated.
• B、You are working on a database where downtime can be tolerated.
• C、You are working on a database that operates in ARCHIVELOG mode.
• D、You are working on a database that operates in NOARCHIVELOG mode.
• E、You are working on a database where all the tablespaces are locally managed.
• F、You are working on a database where control files and redo log files are multiplexed.
• G、You are working on a database where control files and redo log files are not multiplexed.

第3题：

You are working on the PROD database， which is in NOARCHIVELOG mode. You lost the active online redo log group due to a media failure. How should you recover your database？（）

• A、 Restore the database from a whole consistent backup and start the database in MOUNT mode. Then， open the database with the RESETLOGS option after performing a cancel-based recovery.
• B、 Restore the database from a whole consistent backup and start the database in MOUNT mode. Then， drop the lost redo log group and open the database with the RESETLOGS option after performing a cancel-based recovery.
• C、 Restore the database from a whole consistent backup and start the database in MOUNT mode. Then， clear the lost redo log group and open the database with the RESETLOGS option after performing a cancel-based recovery.
• D、 Do nothing. You do not need to recover the database in this case； an instance recovery will be performed by the SMON process on startup.

第4题：

A redo log file is corrupted while the database is open； as a consequence， database operations are stopped because archiving cannot continue. What would you do to solve the problem？（）

• A、 clear the redo log group
• B、 perform redo log file import
• C、 perform an incomplete recovery
• D、 perform a redo log recovery using Recovery Manager （RMAN）
• E、 shut down the database and open the database in the NOARCHIVELOG mode

第5题：

In the parameter file of your production database， the FAST_START_MTTR_TARGET parameter is set to 300 to optimize instance recovery. While observing the performance of the database during instance recovery， you find that the redo log files are not sized properly to support this activity. Which two sources could you use to determine the optimal size of the redo log files？（）

• A、the V$LOG view
• B、the V$DBFILE view
• C、the V$LOGFILE view
• D、the V$INSTANCE_RECOVERY view
• E、Oracle Enterprise Manager Database Control

第6题：

You can control instance recover performance by setting parameters to define targets for（）

• A、The size of the redo buffer in SGA. 
• B、The instance that will perform recovery in Real Application Cluster database. 
• C、The number of blocks to be read during instance recovery, or the time needed to complete instance recovery. 
• D、The number of passes through the redo logs made by the recovery process to identify blocks needing recovery.

第7题：

You are working on a test database where instance recovery takes a considerable amount of time.How can reduce the recovery time？（）

• A、By multiplexing the control files
• B、By multiplexing the redo log files
• C、By decreasing the size of redo log files
• D、By configuring mean time to recover （MTTR） to a lower value
• E、By setting the UNDO_RETENTION parameter to a higher value

第8题：

You configured the Flash Recovery Area （FRA） for your database. The database instance is running inARCHIVELOG mode. The default location for the archived redo log files is the Flash Recovery Area.  Which twofiles are removed automatically if the space is required in the FRA as per the retention policy（）

• A、Flashback log files
• B、Backups that have become obsolete
• C、User managed backups of the data files and control files
• D、Archived redo log files that have multiple copies in a different archive location and not backed up

第9题：

You have configured the flash recovery area to store online redo log files， control files， archived redo logs and RMAN backups. Which of the following files can you successfully delete from the flash recovery area if you want to reclaim the space within it？（）

• A、 multiplexed control files
• B、 RMAN obsolete backups
• C、 multiplexed online redo log files
• D、 archived redo logs that have not been copied to tape

第10题：

The database is running in the ARCHIVELOG mode. It has three redo log groups with one member each. Oneof the redo log groups has become corrupted. You have issued the following command during the recovery of a damaged redo log file:ALTER DATABASE CLEAR UNARCHIVED LOGFILE GROUP 3; Which action should you perform immediately after using this command?（）

• A、You should perform a log switch
• B、You should make a backup of the database
• C、You should switch the database to the NONARCHIVELOG mode
• D、You should shut down the database instance and perform a complete database recovery