1)
Multiplexing the control
file i.e., adding additional control file to the database using spfile
The
following adds another control file named ctrl2.ctl to the databas
Add additional control file in spfile using
alter system set
SQL>alter system set
control_files=’/u01/oradata/ctrl1.ctl’,’/u01/oradata/ctrl2.ctl’ scope=spfile;
shutdown
the database
SQL>shut immediate
add
a additional controlfile in the os level
$Cp
/u01/oradata/ctrl1.ctl /u01/oradata/ctrl2.ctl
connect
to sqlplus
$Sqlplus
/ as sysdba
startup
the database
SQL>startup
SQL>show parameter control_files;
2)
Multiplexing control file
using pfile
SQL>shutdown
database
add additional controlfile in the os
level
$ Cp /u01/oradata/ctrl1.ctl
/u01/oradata/ctrl2.ctl
Make the new changes in mentioned pfile
parameter named control_files
Control_files=’/u01/oradata/ctrl1.ctl’,’
/u01/oradata/ctrl2.ctl’
Startup
the database
SQL>startup
SQL> show parameter control_files;
3)
To take backup of control
file
Below
mentioned script helps us to take binary backup
SQL> alter database backup
controlfile to ‘/u01/app/oracle/backup/control.bkp’;
Below
mentioned script helps us to take text backup of control file
SQL>alter database backup controlfile
to trace;
or
SQL>alter database backup
controlfile to trace as ‘/u01/app/oracle/backup.sql’;
4)
To recreate a control file
The
following procedure takes the backup of control file and recreates the control
file using created script
SQL>alter
database backup controlfile to trace as ‘/home/uclid/control.sql’;
SQL>shut
immediate
$rm
/u01/sr/oradata/control1.ctl
$edit
/ home/sr/control.sql’ and prepare create control file script by removing
all lines up to CREATE CONTROLFILE
SQL>startup
nomount
SQL>@
control.sql
SQL>alter
database open;