HOW TO ADD AND DROP A REDO LOGFILE IN ORACLE
Command to add logfile
kIsH@x3z6zx9<^>alter database add logfile group 4 ('+REDOX','+REDOX') size 109M;
Database altered.
Command to drop logfile
kIsH@x3z6zx9<^>alter database drop logfile '+REDOX/x3z6zx9/onlinelog/group_4.256.1102799287';
Database altered.
or
kish@x3z6zx9<^>alter database drop logfile member '+DATAX/x3z6zx9/onlinelog/group_3.263.1103660751';
Database altered.
or to drop a whole redo group
kIsH@Xhydra<>alter database drop logfile group 5;
Database altered.
kIsH@Xhydra<>alter database drop logfile group 4;
Database altered.
kIsH@Xhydra<>alter database drop logfile group 6;
Database altered.
To add a member to an existing group
kIsH@x3z6zx9<^>alter database add logfile member '+REDOX' to group 7;
Database altered.
To check the list of logfiles
kIsH@x3z6zx9<^>select * from v$logfile;
GROUP# STATUS TYPE
---------- ------- -------
MEMBER
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
IS_
---
3 ONLINE
+DATAX/x3z6zx9/onlinelog/group_3.263.1098264693
NO
3 ONLINE
+RECOX/x3z6zx9/onlinelog/group_3.259.1098264695
YES
2 ONLINE
+DATAX/x3z6zx9/onlinelog/group_2.262.1098264691
NO
2 ONLINE
+RECOX/x3z6zx9/onlinelog/group_2.258.1098264693
YES
1 ONLINE
+DATAX/x3z6zx9/onlinelog/group_1.261.1098264689
NO
1 ONLINE
+RECOX/x3z6zx9/onlinelog/group_1.257.1098264691
YES
4 ONLINE
+REDOX/x3z6zx9/onlinelog/group_4.256.1102799619
NO
4 ONLINE
+REDOX/x3z6zx9/onlinelog/group_4.257.1102799619
NO