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- OCP Oracle 12C Advanced Administration(1Z0-063)
16.
Which are the correct steps, in order, to deal with the loss of an online redo log if the
database has not yet crashed?
1. Issue a checkpoint.
2. Shut down the database.
3. Issue an ALTER DATABASE OPEN command to open the database.
4. STARTUP MOUNT the database.
5. Issue an ALTER DATABASE CLEAR LOGFILE command.
6. Recover all database data files.
1. Issue a checkpoint.
2. Shut down the database.
3. Issue an ALTER DATABASE OPEN command to open the database.
4. STARTUP MOUNT the database.
5. Issue an ALTER DATABASE CLEAR LOGFILE command.
6. Recover all database data files.
- A.1,2,3,4
- B.2,4,5,6
- C.1,2,4,5,3
- D.2,6,4,6,3
- E.2,4,1,3
- Answer & Explanation
- Report
Answer : [C]
Explanation :
Explanation :
| If the database has not shut down yet, you have an opportunity to preserve your data changes. Issue a checkpoint, which will flush dirty buffers to disk. Then shut down the database normally, if possible (SHUTDOWN, SHUTDOWN IMMEDIATE). You then should mount the database with the STARTUP MOUNT command followed by clearing and rebuilding the log file with the ALTER DATABASE CLEAR LOGFILE command. Finally, attempt to open the database with the ALTER DATABASE OPEN command. |
17.
What methods of point-in-time recovery are available in ARCHIVELOG mode?
(Choose all that apply.)
- A.Change-based
- B.Cancel-based
- C.Time-based
- D.Sequence number-based
- E.Transaction number-based
- Answer & Explanation
- Report
Answer : [A, B, C, D]
Explanation :
Explanation :
| Change-based recovery allows you to recover the database to a specific SCN. Cancel-based recovery provides the ability to cancel recovery after each archived redo log application. Time-based recovery provides the ability to recover the database up to a specific point in time. Sequence number–based recovery allows you to recover the database up to a specific log sequence number. |
18.
Which files are required for a full recovery of the database in ARCHIVELOG mode?
(Choose three.)
- A.Database data files
- B.Online redo logs
- C.Archived redo logst
- D.Backup control file
- E.Control file from a backup
- Answer & Explanation
- Report
Answer : [A, C, D]
Explanation :
Explanation :
| To perform a full recovery of the database in ARCHIVELOG mode, you would need the database data files, the archived redo logs, and a backup control file. |
19.
What methods of point-in-time recovery are available in NOARCHIVELOG mode?
- A.Change-based
- B.Cancel-based
- C.Time-based
- D.Sequence number-based
- E.None of the above
- Answer & Explanation
- Report
Answer : [E]
Explanation :
Explanation :
| NOARCHIVELOG mode does not support any kind of point-in-time recovery of the Oracle Database. |
20.
Upon starting your ARCHIVELOG mode 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:
1. Restore the database data files.
2. Issue the ALTER DATABASE CLEAR UNARCHIVED LOGFILE GROUP command.
3. Issue the ALTER DATABASE OPEN command.
4. Issue the ALTER DATABASE OPEN RESETLOGS command.
5. Recover the database using point-in-time recovery.
6. Issue the STARTUP MOUNT command to mount the database.
7. Back up the database.
Which is the correct order of these steps in this case?
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:
1. Restore the database data files.
2. Issue the ALTER DATABASE CLEAR UNARCHIVED LOGFILE GROUP command.
3. Issue the ALTER DATABASE OPEN command.
4. Issue the ALTER DATABASE OPEN RESETLOGS command.
5. Recover the database using point-in-time recovery.
6. Issue the STARTUP MOUNT command to mount the database.
7. Back up the database.
Which is the correct order of these steps in this case?
- A.1,6,5,4,7
- B.6,5,4
- C.6,2,3,7
- D.1,6,3
- E.The database cannot be recovered.
- Answer & Explanation
- Report
Answer : [C]
Explanation :
Explanation :
| You should first start the database in mount mode using the STARTUP MOUNT command. You then issue the ALTER DATABASE CLEAR UNARCHIVED LOGFILE command. This will clear the log file if it needs to be archived and recreate the online redo log group. If that command is successful, then you issue the ALTER DATABASE OPEN command. The last step, backing up the database, is very important since your previous backup will not be able to recover the database beyond the point of the cleared redo log sequence number. This is because you have skipped a redo log in the redo log stream. |
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