单选题You are attempting to clear an unarchived redo log file. In order to manually enact a log switch, which of the following statements is appropriate?（）A ALTER DATABASE B ALTER SYSTEM C ALTER USER D ALTER REDO LOG

第1题：

Your database is in ARCHIVELOG mode. You have two online redo log groups, each of which contains one redo member. When you attempt to start the database, you receive the following errors: ORA-00313: open failed for members of log group 1 of thread 1 ORA-00312: online log 1 thread 1: 'D:/REDO01.LOG' You discover that the online redo log file of the current redo group is corrupted. Which statement should you use to resolve this issue?（）

• A、ALTER DATABASE DROP LOGFILE GROUP 1;
• B、ALTER DATABASE CLEAR LOGFILE GROUP 1;
• C、ALTER DATABASE CLEAR UNARCHIVED LOGFILE GROUP 1;
• D、ALTER DATABASE DROP LOGFILE MEMBER 'D:/REDO01.LOG

第2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3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4题：

You are attempting to clear an unarchived redo log file. In order to manually enact a log switch, which of the following statements is appropriate?（）

• A、ALTER DATABASE 
• B、ALTER SYSTEM 
• C、ALTER USER 
• D、ALTER REDO LOG

第5题：

When performing an online backup，what is the proper order of the following steps？（）   a. Issue the alter database end backup command. b. Back up the archived redo logs. c. Issue the alter database begin backup command.  d. Back up the database files.  e. Determine the beginning log sequence number. f. Determine the ending log sequence number.  g. Force a log switch with the alter system switch logfile command.

• A、a， b， c， d， e， f， g
• B、c， d， a， b， e， g， f
• C、f， d， b， g， a， c， e
• D、e， c， d， a， g， f， b
• E、a， f， b， g， e， c， d

第6题：

User SCOTT wants to back out the transactions on the REGIONS table in his schema. As a DBA， which commands must you execute to enable SCOTT to flash back the transactions？（）

• A、 ALTER DATABASE FLASHBACK ON
• B、 GRANT SELECT any transaction TO scott
• C、 GRANT EXECUTE ON dbms_flashback TO scott
• D、 ALTER DATABASE ADD SUPPLEMENTAL LOG DATA
• E、 ALTER TABLESPACE undots1 RETENTION GUARANTEE
• F、 ALTER DATABASE ADD SUPPLEMENTAL LOG DATA （PRIMARY KEY） COLUMNS

第7题：

You have lost all your online redo logs. As a result， your database has crashed. You have tried to restart the database and clear the online redo log files， but when you try to open the database you get the following error.   SQL> startup ORACLE instance started.  Total System Global Area 167395328 bytes Fixed Size 1298612 bytes Variable Size 142610252 bytes Database Buffers 20971520 bytes Redo Buffers 2514944 bytes Database mounted.  ORA-00313： open failed for members of log group 2 of thread 1 ORA-00312： online log 2 thread 1： ，，/oracle01/oradata/orcl/redo02a.log ORA-27037： unable to obtain file status Linux Error： 2： No such file or directory Additional information： 3  ORA-00312： online log 2 thread 1： ，，/oracle01/oradata/orcl/redo02.log ORA-27037： unable to obtain file status Linux Error： 2： No such file or directory Additional information： 3  SQL> alter database clear logfile group 2； alter database clear logfile group 2 * ERROR at line 1：  ORA-01624： log 2 needed for crash recovery of instance orcl （thread 1） ORA-00312： online log 2 thread 1： ，，/oracle01/oradata/orcl/redo02.log ORA-00312： online log 2 thread 1： ，，/oracle01/oradata/orcl/redo02a.log   What steps must you take to resolve the error？（） a. Issue the recover database redo logs command.  b. Issue the Startup Mount command to mount the database.  c. Restore the last full database backup.  d. Perform a point-in-time recovery， applying all archived redo logs that are available.  e. Restore all archived redo logs generated during and after the last full database backup.  f. Open the database using the alter database open resetlogs command.  g. Issue the alter database open command.

• A、b， a， f
• B、e， b， a， f
• C、e， b， a， g
• D、b， a， g
• E、c， e， b， d， f

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第13题：

User SCOTT wants to back out the transactions on the REGIONS table in his schema. As a DBA, which commands must you execute to enable SCOTT to flash back the transactions?（）

• A、ALTER DATABASE FLASHBACK ON;
• B、GRANT SELECT any transaction TO scott;
• C、GRANT EXECUTE ON dbms_flashback TO scott;
• D、ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;
• E、ALTER TABLESPACE undots1 RETENTION GUARANTEE;
• F、ALTER DATABASE ADD SUPPLEMENTAL LOG DATA (PRIMARY KEY) COLUMNS;

第14题：

Upon starting your database， you receive the following error：   SQL> startup ORACLE instance started.  Total System Global Area 171581440 bytes Fixed Size 1298640 bytes Variable Size 146804528 bytes Database Buffers 20971520 bytes Redo Buffers 2506752 bytes Database mounted.  ORA-00313： open failed for members of log group 1 of thread 1  ORA-00312： online log 1 thread 1： ’/oracle01/oradata/orcl/redo01.log’ ORA-00312： online log 1 thread 1： ’/oracle01/oradata/orcl/redo01a.log’   You can choose from the following steps：   a. Restore the database datafiles.  b. Issue the alter database clear unarchived logfile group 1 command. c. Issue the alter database open command.  d. Issue the alter database open resetlogs command.  e. Recover the database using point-in-time recovery. f. Issue the Startup Mount command to mount the database.  g. Back up the database.  Which is the correct order of these steps in this case？（）

• A、a， f， e， d， g
• B、f， e， d
• C、f， b， c， g
• D、a， f， c
• E、The database cannot be recovered.

第15题：

如何强制执行日志切换（）

• A、ALTER SYSTEM CHECKPOINT;
• B、ALTER SYSTEM CHECKPOINT FORCE;
• C、ALTER SYSTEM SWITCH LOGFILE;
• D、ALTER SYSTEM SWITCH LOGFILE FORCE;
• E、ALTER DATABASE LOG SWITCH;

第16题：

To allocate another role to a user, which command is most appropriate?（）

• A、ALTER USER 
• B、ALTER DATABASE 
• C、ALTER SYSTEM 
• D、GRANT

第17题：

Your database is in ARCHIVELOG mode. You have two online redo log groups，each of which contains one redo member.  When you attempt to start the database， you receive the following errors：（）

• A、 ALTER DATABASE DROP LOGFILE GROUP 1
• B、 ALTER DATABASE CLEAR LOGFILE GROUP 1
• C、 ALTER DATABASE CLEAR UNARCHIVED LOGFILE GROUP 1
• D、 ALTER DATABASE DROP LOGFILE MEMBER ’D:///REDO01.LOG’

第18题：

You have the following online redo log configuration：    Group       Member   1     ’/disk1/oradata/redo01a.log’   2     ’/disk2/oradata/redo02a.log’   3     ’/disk3/oradata/redo03a.log’   You decide to multiplex the online redo log groups for recovery of redo log files in case of any disaster. Which two statements will you NOT issue to multiplex the online redo log files？（）

• A、 ALTER DATABASE ADD LOGFILE MEMBER ’/disk1/oradata/redo01b.log’ TO GROUP 1；
• B、 ALTER DATABASE ADD LOGFILE MEMBER ’/disk2/oradata/redo01b.log’ TO GROUP 1；
• C、 ALTER DATABASE ADD LOGFILE MEMBER ’/disk1/oradata/redo02b.log’ TO GROUP 2；
• D、 ALTER DATABASE ADD LOGFILE MEMBER ’/disk2/oradata/redo02b.log’ TO GROUP 2；
• E、 ALTER DATABASE ADD LOGFILE MEMBER ’/disk1/oradata/redo3b.log’ TO GROUP 3；
• F、 ALTER DATABASE ADD LOGFILE MEMBER ’/disk2/oradata/redo3b.log’ TO GROUP3；

第19题：

Your database is in ARCHIVELOG mode. You have two online redo log groups each of which contains one redo member. When you attempt to start the database， you receive the following errors：   ORA-00313： open failed for members of log group 1 of thread 1   ORA-00312： online log 1 thread 1： ’D:///REDO01.LOG’   You discover that the online redo log file of the current redo group is corrupted.  Which statement should you use to resolve this issue？（）

• A、 SQL>ALTER DATABASE DROP LOGFILE GROUP 1；
• B、 SQL>ALTER DATABASE CLEAR LOGFILE GROUP 1；
• C、 SQL>ALTER DATABASE CLEAR UNARCHIVED LOGFILE GROUP 1；
• D、 SQL>ALTER DATABASE DROP LOGFILE MEMBER ’D:///REDO01.LOG’；

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