How to add a redo log member to an existing redo log group in an Oracle database | Redo log files Multiplexed

Add a redo log member to an existing redo log group in an Oracle database

SQL> select group#,status,member from v$logfile;

    GROUP# STATUS

---------- -------

MEMBER

--------------------------------------------------------------------------------

         3

/u01/app/oracle/oradata/DB1/redo03.log

         2

/u01/app/oracle/oradata/DB1/redo02.log

         1

/u01/app/oracle/oradata/DB1/redo01.log

SQL>

SQL> select group#,members,archived,status from v$log;

    GROUP#    MEMBERS ARC STATUS

---------- ---------- --- ----------------

         1          1 NO  CURRENT

         2          1 YES INACTIVE

         3          1 YES INACTIVE

SQL>

SQL> alter database add logfile member '/u01/app/oracle/oradata/DB1/redo01b.log' to group 1;

Database altered.

SQL> select member from v$logfile;

MEMBER

--------------------------------------------------------------------------------

/u01/app/oracle/oradata/DB1/redo03.log

/u01/app/oracle/oradata/DB1/redo02.log

/u01/app/oracle/oradata/DB1/redo01.log

/u01/app/oracle/oradata/DB1/redo01b.log

SQL> 

Best Practices & Notes

Always add members on different disks for redundancy.

The new log file must not exist already on disk.

All members of a group are written to simultaneously — they are identical.

Adding a member does not affect the database availability.