ADD/DROP Redo logfile groups:
GROUP# THREAD# STATUS
---------- ---------- ----------------
1 1 INACTIVE
2 1 CURRENT
3 1 INACTIVE
SHAIKDB>alter database drop logfile group 1;
Database altered.
SHAIKDB>alter database drop logfile group 3;
alter database drop logfile group 3
*
ERROR at line 1:
ORA-01567: dropping log 3 would leave less than 2 log files for instance SHAIKDB (thread 1)
ORA-00312: online log 3 thread 1: '/u01/app/oracle/SHAIKDB/redo03.log'
SHAIKDB>alter database add logfile group 1('/u01/app/oracle/SHAIKDB/redo1.log','/u01/app/oracle/SHAIKDB/redo12.log') size 100m;
Database altered.
SHAIKDB>alter database drop logfile group 3;
Database altered.
SHAIKDB>alter database add logfile group 3 ('/u01/app/oracle/SHAIKDB/redo3.log','/u01/app/oracle/SHAIKDB/redo31.log') size 100m;
Database altered.
SHAIKDB>select group#,thread#,status from v$log;
GROUP# THREAD# STATUS
---------- ---------- ----------------
1 1 UNUSED
2 1 CURRENT
3 1 UNUSED
SHAIKDB>alter system archive log current;
System altered.
SHAIKDB>select group#,thread#,status from v$log;
GROUP# THREAD# STATUS
---------- ---------- ----------------
1 1 CURRENT
2 1 ACTIVE
3 1 UNUSED
SHAIKDB>alter system archive log current;
System altered.
SHAIKDB>select group#,thread#,status from v$log;
GROUP# THREAD# STATUS
---------- ---------- ----------------
1 1 ACTIVE
2 1 ACTIVE
3 1 CURRENT