The database instance is currently using SPFILE. View the Exhibit and examine the error that you
received while running the DB Structure Integrity check. Given below are the steps to recover from
the error in random order:
1. Shut down the instance, if not already done.
2. Copy one of the remaining control files to a new location.
3. Change the value of the CONTROL_FILES initialization parameter to correspond to the new
location of the control files.
4. Start up the database instance to the NOMOUNT stage.
5. Recover the database to the point of failure of the control file.
6. Open the database.
Identify the correct sequence of steps?
A.
1, 2, 4, 3, 5, 6
B.
2, 4, 3, 5, 6; 1 not required
C.
4, 5, 6, 2, 3; 1 not required
D.
5, 2, 3, 4; 1 and 6 not required
Exhibit not showing
Control File (controlfile) Loss Recovery
File -based control of complex multi-path , its loss is divided into two, one of which is a control file is damaged or missing , and the other is all the control files are missing . Based on the first case, only the good control file copy in case of damage or loss of the control file path. In the second case you need to restore or rebuild the control file manually via the control file backup information .
Open Database
To open a database, you must meet the following criteria :
• All control files must exist and synced
• all online data files must exist and synced
• Each redo log group must have at least one member exists
Open Database
When the database is shut down from the stage to a fully open stage, the database will perform an internal consistency check following stages:
• NOMOUNT: Examples To achieve NOMOUNT (also known STARTED) status, it must read the initialization parameter file. NOMOUNT instance enters the state, does not check any database file.
• MOUNT: enter MOUNT state instance, it will check whether all control files initialization parameters listed in the file are present and synchronized. Even if there is a control file is missing or damaged, examples will return an error to the administrator
(Specified in the control file is missing) and keep NOMOUNT state.
• OPEN: MOUNT instance from the OPEN state to state, it performs the following actions:
– Check all known control redo log file group is at least one member present. Any member missing will be recorded in the alert log.
– Verify all known control file data file exists, but does not verify the offline files.
Before an administrator tries to bring an offline file online, these files are not checked. If the data file does not belong to the SYSTEM or UNDO table space, the administrator can make the data files offline and open instance. If any files are missing
Member, it returns an error to the administrator, first pointed out a missing file, then instance remains MOUNT state. When an instance of finding the missing file, an error message is displayed only the first file is causing the problem. To find the need to restore all the files, administrators can get a complete list of files that need attention by checking the v $ recover_file dynamic performance views: Open Database
When the database is shut down from the stage to a fully open stage, the database will perform an internal consistency check following stages:
• NOMOUNT: Examples To achieve NOMOUNT (also known STARTED) status, it must read the initialization parameter file. NOMOUNT instance enters the state, does not check any database file.
• MOUNT: enter MOUNT state instance, it will check whether all control files initialization parameters listed in the file are present and synchronized. Even if there is a control file is missing or damaged, examples will return an error to the administrator
(Specified in the control file is missing) and keep NOMOUNT state.
• OPEN: MOUNT instance from the OPEN state to state, it performs the following actions:
– Check all known control redo log file group is at least one member present. Any member missing will be recorded in the alert log.
– Verify all known control file data file exists, but does not verify the offline files.
Before an administrator tries to bring an offline file online, these files are not checked. If the data file does not belong to the SYSTEM or UNDO table space, the administrator can make the data files offline and open instance. If any files are missing
Member, it returns an error to the administrator, first pointed out a missing file, then instance remains MOUNT state. When an instance of finding the missing file, an error message is displayed only the first file is causing the problem. To find the need to restore all the files, administrators can get a complete list of files that need attention by checking the v $ recover_file dynamic performance views:
SQL> startup
ORACLE instance started.
Total System Global Area 171966464 bytes
Fixed Size 775608 bytes
Variable Size 145762888 bytes
Database Buffers 25165824 bytes
Redo Buffers 262144 bytes
Database mounted.
ORA-01157: can not identify / lock data file 4 – see DBWR trace file
ORA-01110: data file 4: ‘/oracle/oradata/orcl/users01.dbf’
SQL> SELECT name, error FROM v $ datafile JOIN v $ recover_file USING (file #);
NAME ERROR
———————————– ————— —
/oracle/oradata/orcl/users01.dbf FILE NOT FOUND
/oracle/oradata/orcl/example01.dbf FILE NOT FOUND
– Verify that all but offline data files or read-only data files synchronized with the control file. When necessary, the instance will automatically perform recovery. However, if a file is not synchronized, resulting in not using the online redo
Chi group recover, an administrator must perform media recovery. If any of the files need media recovery, then returns an error message to the administrator, first pointed out the need to restore a file, then instance remains MOUNT status:
ORA-01113: file 4 needs media recovery
ORA-01110: data file 4: ‘/oracle/oradata/orcl/users01.dbf’
In addition, v $ recover_file note provides a complete list of files. Lists and requires media recovery file exists, but does not display an error message.
Make the database maintained in the open state
After opening the database, if the following keys are missing, the database will fail:
• Any control files
• belong to the system table space or table space restore data files
• The entire redo log group (as long as there is at least one member of the group is available, the instance will remain open.)
Make the database maintained in the open state
After opening the database, the following media failure may cause instance failure: loss of control files, redo log is missing the entire group, or lost part of the SYSTEM or UNDO tablespace data files. Even the loss of an inactive redo log group, the database will eventually fail because of a log switch.
In many cases, the failed samples are not fully closed, but can not continue to work. Close up of the database must be in the situation to recover from these types of media failure. Therefore, the administrator must perform SHUTDOWN ABORT command before you can start back to work.
Lost belonging to other table space data file does not cause the instance to fail, and can recover the database while the database is open, then the other table space in the work can proceed.
Check the alert log file or by using a data recovery instructions, can detect these errors.