多选题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（）AThe online redo log files and online data files 

第1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2题：

You have to shut down the database instance with the ABORT option because of a hardware failure. Which statement is true about the subsequent opening of the database？（）

• A、The database would open normally.
• B、The database would not open， and it would stop at mount stage.
• C、The database would open after automatically performing instance recovery.
• D、The database would not open， and you have to perform database recovery to open it.

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：

You work as a database administrator for Supportcenter.cn. You started the instance using theinit.orafile. You have two control files and three redo log groups in your database. You decided to protect the database against failures by adding one more control file. Which file is the appropriate way to perform this task？（）

• A、Shut down the instance， copy the control file to the third location and open the database.
• B、Abort the instance， copy the control file to the third location， modify the CONTROL_FILES parameter in theinit.orafile and open the database.
• C、Copy the control file to the third location， modify the CONTROL_FILES parameter in theinit.orafile， restart the instance and open the database.
• D、Shut down the instance， copy the control file to the third location， modify the CONTROL_FILES parameter in theinit.orafile and open the database.
• E、Shut down the instance， startup in the mount state， copy the control file to the third location， modify the CONTROL_FILES parameter ininit.oraand open the database.

第5题：

You work as a database administrator for Certkiller .com. Your database is in the MOUNT state and you execute the following command to open it ALTER DATABASE OPEN； What two actions are performed as a result of this command？（）

• A、All control files are opened
• B、All redo files are opened
• C、The password file is opened
• D、The parameter file is opened
• E、All online data files are opened

第6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7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8题：

If a log file becomes corrupted， it may cause the database to stall. How would you correct such a situation？（）  

• A、 Recover the online redo log from backup.
• B、 Delete and re-create the log file.
• C、 Use the alter database clear logfile command to clear the log file.
• D、 Shut down the database and restart it.
• E、 Shut down the database and then mount it. Clear the log file with the alter database clear logfile command and then restart the database with alter database open resetlogs.

第9题：

After performing a clean shut down of the database instance for maintenance， you mount thedatabase and then 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：

our database is in the MOUNT state and you execute the following command to open it：  ALTER DATABASE OPEN  What two actions are performed as a result of this command？（）

• A、All control files are opened.
• B、All redo log files are opened
• C、The password file is opened.
• D、The parameter file is opened.
• E、All online data files are opened.