Oracle Database Backup Recovery, inspection object settings and related recovery Overview

Database backup and recovery, inspection object settings to be concerned: 1. database Name, and DBID; -- dbid in v $ database SYS @ ORCLselectdbid, namefromv $ database; DBIDNAME-------------------1385095721ORCL2. location of the control file; showparametercontrol_files; selectnamefr

Database backup and recovery, inspection object settings to be concerned: 1. database name, and DBID; -- dbid in v $ database SYS @ ORCLselect dbid, NAME from v $ database; DBID name ---------- ------- 1385095721 ORCL 2. location of the control file; show parameter control_files; select name fr

Database backup and recovery, inspection needs to pay attention to the object settings:

1. database Name and DBID; -- dbid is in v $ database
SYS @ ORCL> select dbid, name from v $ database;

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

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

3. Log File Location and database archiving settings;
Select log_mode from v $ database;
Archive log list;

Select * from v $ log;
Select * from v $ logfile;
-- Focus on the number, size, status, and location of log groups;
Select * from v $ archived_log;

4. data file location, size, and status;
Select * from dba_tablespaces;
Select * from v $ tablespace;
Select * from dab_data_files;
Select * from v $ datafile;
-- In the 11 GB database, you only need to pay attention to the size of the temporary tablespace;

5. parameter file;
Show parameter spfile;

6. alarm logs;
Select * from v $ diag_info;
Adrci

7. Existing Database Backup policies and backup sets;

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

1. All control files must exist and have been synchronized

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

After you open the database, the database will fail if the following items are lost:

1. Any control file
2. data files belonging to the system or restored tablespace
3. The entire redo log group (as long as at least one member in the group is available, the instance will remain open)

If the control file is lost or damaged, the instance is usually aborted. You must perform the following steps:

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

2. Copy the existing control file to restore the missing control file.
3. Start the instance.

If a member in the redo log file group is lost and at least one member exists in the group, note the following:

The normal operation of the instance is not affected.

The Alert Log receives a message notifying you that a member cannot be found.

You can copy a remaining file from the same group to restore the missing log file.

Data files are lost in NOARCHIVELOG mode.

If the database is in NOARCHIVELOG mode and any data files are lost, you need to completely restore the database, including the control file and

There are data files.
When the database is in NOARCHIVELOG mode, it can only be restored to the status of the last backup. Therefore, the user must re-enter

Changes made since the last backup.

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. Ask the user to re-enter all changes made since the last backup.

If a database in NOARCHIVELOG mode has an incremental backup policy. Then RMAN restores the nearest 0 level, and then RMAN restores

And then apply Incremental backup.

Key System data files are lost in ARCHIVELOG mode.

If a data file is lost or damaged and belongs to the SYSTEM or UNDO tablespace,
Perform the following tasks:

1. The instance may or may not be automatically closed. If the instance 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.