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 configur

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：

The database is running in the ARCHIVELOG mode. It has three redo log groups with one member each. One of 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

第3题：

第4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5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 want to use the automatic management of backup and recovery operations features for your database.Which configuration must you set?（）

• A、Enable the flash recovery area and specify it as the archived redo log destination.
• B、Disable the flash recovery area and start the database instance in ARCHIVELOG mode.
• C、Enable the flash recovery area but do not specify it as the archived redo log destination.
• D、Disable the flash recovery area and start the database instance in NOARCHIVELOG mode

第8题：

The instance abnormally terminates because of a power outage.  Which statement is true about redo log filesduring instance recovery（）

• A、Inactive and current redo log files are required to accomplish recovery.
• B、Online and archived redo log files are required to accomplish instance recovery.
• C、All redo log entries after the last checkpoint are applied from redo log files to data files.
• D、All redo log entries recorded in the current redo log file until the checkpoint position are applied to data files

第9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10题：

You are maintaining your database in Oracle10g. You have set the value of the STATISTICS_LEVEL initialization parameter to TYPICAL and the value of the FAST_START_MTTR_TARGET parameter to 900 seconds. To increase the performance of the database， you want to determine the log file size that should equal the minimum size of all the online redo log files. Which column will enable you to perform the desired task？（）

• A、 the WRITES_LOGFILE_SIZE column of the V$INSTANCE_RECOVERY view
• B、 the column of the V$INSTANCE_RECOVERY view
• C、 the OPTIMAL_LOGFILE_SIZE column of the V$INSTANCE_RECOVERY view
• D、 the LOG_FILE_SIZE_REDO_BLKS column of the V$INSTANCE_RECOVERY view