Redo Logfile Management



1)     To see the redo log files
             SQL>select member from v$logfile;
2)     To add online redolog file groups
            SQL>alter database add logfile group 4 ('/u01/app/sr/oradata/dbca/redo4.log') size 5m;
            SQL>select member from v$logfile;
3)     Adding online redo log file members
            SQL>alter database add logfile member ‘/u01/app/sr/oradata/dbca/redo4a.log’ to group 4;
4)     Renaming online redo log files;
            Shutdown the database
            SQL>shutdown immediate
            Rename the redo log files with new name in os level
            SQL>exit
            Goto logfile location
            $ mv redo4a.log redo4b.log
            Connect to sqlplus
            Startup the database in mount state
            SQL>startup mount
SQL>alter database rename file ‘/u01/app/sr/oradata/dbca/redo4a.log’ to ‘/u01/app/sr/oradata/dbca/redo4b.log’;
             SQL>alter database open;
            SQL>select member from v$logfile;
5)     Relocating online redo logfiles
SQL> Shutdown the database
            SQL>shutdown immediate
             Relocate the redo logfiles in new location
            SQl>exit
            Goto logfile location
             $ cp redo4a.log /u01/app/sr/oradata/
             Connect to sqlplus
            SQL>startup mount
            SQL>alter database rename file /’u01/app/sr/oradata/dbca/redo4a.log’ to ‘/u01/app/uclid/oradata/redo4a.log’;
6)     To check the status of redo logfile group
SQL>select group#,status from v$log;
7)     Dropping Online redo logfile group
The following drops the online redo log group that is INACTIVE. We cannot drop the redo logs that are in CURRENT and ACTIVE state.
SQL> alter database drop logfile group 4;
8)     Dropping online redo logfile members
We cannot drop redo log file members if the redo log groups having only one member and both ‘CURRENT’ log file members we can’t.
SQL>alter database drop logfile member ‘/u01/app/sr/oradata/redo4a.log’;