Backup and recovery of Oracle log files, parameter files, and control files

To understand the role of each file, you must master the basic concepts of Oracle.

I. backup and recovery of Oracle basic files

1. logfile diversification and Backup Recovery

Log query

Select * from v $ logfile;

Select * from v $ log;

Manually switch logs

Alter system switch logfile;

Manual checkpoint

Alter system checkpoint;

Alarm Log File

Show paramter dump

$ ORACLE_BASE/admin/orcl/bdump

Tail-f alert *. log

Diversified log files

Alter database add logfile member '/opt/ora10g/oradata/orcl/redo01B. log' to group 1;

Alter database add logfile member '/opt/ora10g/oradata/orcl/redo02B. log' to group 2;

Alter database add logfile member '/opt/ora10g/oradata/orcl/redo03B. log' to group 3;

The log file is broken, and the log file is repaired (this can be used to restore the file if it is lost)

Alter database clear logfile group 1;

If not

Alter database clear unarchived logfile group 2;

Add Member

Alter database add logfile group 4;

Alter database add logfile member '/opt/ora10g/oradata/orcl/redo04.log' to group 4;

Delete a log Group

Alter database drop logfile group 4;

Delete a Member from a log Group

Alter database drop logfile member '/opt/ora10g/oradata/orcl/redo01B. log ';

2. parameter file backup and recovery

Use pfile to back up binary startup parameter files

Create pfile from spfile;

If the spfile file is lost or damaged

Startup pfile = '... INIT <ORACLE_SID>. ora'

Create spfile from pfile

Startup force

Show parameter spfile

3. Control File Backup Recovery

Diversified Control Files

The control file records and maintains the physical structure of the database, and also records the backup and recovery information. If the database only has one control file,

When the media fails and the control file is damaged, the database cannot be loaded. If the file backup is not controlled, it will be a disaster,

Therefore, you need to diversify the control files and distribute them on different disks.

Query existing control files:

SQL> select name from v $ controlfile;

Initialization parameter control_files:

Alter system set control_files = '/disk1/ora10g/oradata/orcl/control01.ctl', '/disk1/ora10g/oradata/orcl/control02.ctl ', '/disk1/ora10g/oradata/orcl/control03.ctl', '/disk1/ora10g/control01.ctl' scope = spfile;

Close the database:

SQL> shutdown immediate;

Copy control file:

SQL> host cp/disk1/ora10g/oradata/orcl/control01.ctl/disk1/ora10g/control01.ctl

Start the database:

SQL> startup

 

Backup Control File

A. Back up the control file as a binary file

SQL> alter database backup controlfile to 'I: \ oracle \ backup \ control. bkp ';

In this way, you can directly go back to cp.

 

B. Back up the control file as a text file (back up it to the tracking file under the oracle \ base \ admin \ sid \ udump directory, and generate an SQL script in the tracking file)

Recovery is also very easy. Find the trace file and open it and find something similar to the following:

STARTUP NOMOUNT

Create controlfile reuse database "ORCL" RESETLOGS NOARCHIVELOG

MAXLOGFILES 16

MAXLOGMEMBERS 3

MAXDATAFILES 100

MAXINSTANCES 8

# MAXLOGHISTORY 292

LOGFILE

GROUP 1 (

'/Disk1/ora10g/oradata/orcl/redo01.log ',

'/Disk1/ora10g/oradata/orcl/redo01B. Log'

) SIZE 50 M,

GROUP 2 (

'/Disk1/ora10g/oradata/orcl/redo02.log ',

'/Disk1/ora10g/oradata/orcl/redo02B. Log'

) SIZE 50 M,

GROUP 3 (

'/Disk1/ora10g/oradata/orcl/redo03.log ',

'/Disk1/ora10g/oradata/orcl/redo03B. Log'

) SIZE 50 M

-- STANDBY LOGFILE

DATAFILE

'/Disk1/ora10g/oradata/orcl/system01.dbf ',

'/Disk1/ora10g/oradata/orcl/undotbs01.dbf ',

'/Disk1/ora10g/oradata/orcl/sysaux01.dbf ',

'/Disk1/ora10g/oradata/orcl/users01.dbf ',

'/Disk1/ora10g/oradata/orcl/example01.dbf'

Character set WE8ISO8859P1

;

Directly create an SQL file and call it through.

Then alter database open rsetlogs;

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