Ü CONTROL FILE STORE INFORMATION
q DATABASE NAME
q TIMESTAMP OF DATABASE CREATION
q NAME AND LOCATION OF DATA FILES AND REDO LOG FILES
q TABLESPACE INFORMATION
q ARCHIVED LOG INFORMATION
q BACKUP SET AND BACKUP PIECE INFORMATION
q CURRENT LOG SEQUENCE NUMBER [SCN]
q CHECKPOINT INFORMATION
& Minimum one controlfile needed but recommended at
least two controlfile.
q SQL> desc v$controlfile
Name
Null? Type
----------------------------------------- --------
----------------------------
STATUS
VARCHAR2(7)
NAME
VARCHAR2(513)
IS_RECOVERY_DEST_FILE VARCHAR2(3)
BLOCK_SIZE
NUMBER
FILE_SIZE_BLKS
NUMBER
CON_ID
NUMBER
q SQL> select name, block_size from v$controlfile;
NAME
BLOCK SIZE
---------------------------------------------------------------------------------
-------------------
/u01/app/oracle/oradata/ORCLCDB/control01.ctl 16384
/u01/app/oracle/fast_recovery_area/ORCLCDB/control02.ctl
16384
q SQL> show parameter control_files
NAME
TYPE
VALUE
------------------------------------ ----------- ------------------------------
control_files
string
/u01/app/oracle/oradata/PROD/c
ontrol01.ctl, /u01/app/oracle/
fast_recovery_area/PROD/contro
l02.ctl
Ü
CONTROL FILE MULTIPLEXING
q [oracle@19c dbs]$ sqlplus / as sysdba
SQL*Plus: Release 19.0.0.0.0 - Production on Fri Sep 1 22:04:32
2023
Version 19.3.0.0.0
Copyright (c) 1982, 2019, Oracle. All rights reserved.
Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 -
Production
Version 19.3.0.0.0
q SQL> show con_name
CON_NAME
------------------------------
CDB$ROOT
q SQL> alter system set
control_files='/u01/app/oracle/oradata/PROD/control01.ctl','/u01/app/oracle/fast_recovery_area/PROD/control02.ctl','/u01/app/oracle/oradata/PROD/control03.ctl'
scope=spfile;
System altered.
q SQL> shu immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
q SQL> exit
Disconnected from Oracle Database 19c Enterprise Edition Release
19.0.0.0.0 - Production
Version 19.3.0.0.0
q [oracle@dbserver ~]$ cp /u01/app/oracle/oradata/PROD/control01.ctl
/u01/app/oracle/oradata/PROD/control03.ctl
q SQL> startup
ORACLE instance started.
Total System Global Area 1660941680 bytes
Fixed
Size
9135472 bytes
Variable Size
973078528 bytes
Database Buffers
671088640 bytes
Redo
Buffers
7639040 bytes
Database mounted.
Database opened.