Oracle database backup recovery, patrol needs to focus on object settings and related recovery overview

Database backup recovery, patrol needs to focus on the object settings:

1. Database name, and dbid;--dbid in V$database
[email protected]>select dbid,name from V$database;

DBID NAME
---------- ---------
1385095721 ORCL

2. Control the location of the file;
Show parameter control_files;
Select name from V$controlfile;

3. Location of log files and archiving settings of the database;
Select Log_mode from V$database;
Archive log list;

SELECT * from V$log;
SELECT * from V$logfile;
--focus on the number of log groups, size, status, location;
SELECT * from V$archived_log;

4. Data file location, size, status;
SELECT * from Dba_tablespaces;
SELECT * from V$tablespace;
SELECT * from Dab_data_files;
SELECT * from V$datafile;
--In a 11g database, the temporal table space only needs to focus on its size;

5. parameter file;
Show parameter SPFile;

6. Alarm log;
SELECT * from V$diag_info;
Adrci

7. Database existing backup policy, backup set situation;

To open a database, the following conditions must be met:

1. All control files must be present and synchronized

2. All online data files must be present and synchronized
3. Each redo log group must have at least one member present

When the database is opened, the database fails if the following items are missing:

1. Any control file
2. Data files that are part of the system or restore table space
3. The entire Redo log group (the instance remains open as long as at least one member of the group is available)

If the control file is missing or corrupted, the instance is typically aborted. Then, you must perform the following steps:

1. Close the instance (if it is still open).

2. Restore the missing control file by copying the existing control file.
3. Launch the instance.

If you lose a member of the Redo log file group, and there is at least one member in the group, be aware of the consequences:

does not affect the normal operation of the instance.

You receive a message in the alert log informing you that a member could not be found.

You can restore a missing log file by copying one of the remaining files from the same group.

Data file lost in Noarchivelog mode

If the database is in Noarchivelog mode and any data files are missing, you need to fully restore the database, including the control file and the

There are data files.
When the database is in Noarchivelog mode, it can only revert to the state at the time of the last backup. Therefore, the user must re-enter the

The changes that were made since the last backup.

Please perform the following tasks:

1. If the instance has not been closed, close the instance.
2. Restore the entire database from backup, including all data files and control files.

3. Open the database.

4. Let the user reenter all changes made since the last backup.

If the database in Noarchivelog mode has an incremental backup policy. Then Rman reverts to the nearest level 0, then Rman recovers into

Incremental backup is applied to the process.

System Critical data file lost in ARCHIVELOG mode

If a data file is missing or damaged, and the file belongs to the SYSTEM or UNDO table space,
Please perform the following tasks:

1. Instances may or may not be turned off automatically. If it is not automatically closed, use SHUTDOWN ABORT to close the instance.

2. Load the database.
3. Restore and restore the missing data files.

4. Open the database.

Oracle database backup recovery, patrol needs to focus on object settings and related recovery overview