Clearing corrupt redo log files

The database cannot be brought back to a good state using the database recovery procedures if the redo log files have a problem. Be aware of the following error:

ORA-00255: error archiving log name of thread num, sequence # num

If you experience this error, you must clear the redo log file.

To clear corrupt redo log files

Check the accompanying message stack for more detailed information. If the online log is corrupted, then the log file can be cleared using the UNARCHIVED option.

An example is a report that the redo log file group 2 is corrupt.
Log in as user oracle (Solaris) or AgfaService (Windows).
Type the following:
cd
sqlplus /nolog
connect sys/stayout as sysdba
When you are connected, type:
select * from v$log;
Match the sequence number to the first column group number (group #). Use that group number (#) in the following step.
When you see 3 rows selected, type
alter database clear unarchived logfile group #;
When the statement is processed, type:
select * from v$log;
When you see 3 rows selected, type
alter system switch logfile;
When the statement is processed, type:
select * from v$log;
If the database is not open yet, type:
alter database open;
After the redo logfile is cleared, you must manually back up the database.

If you do not perform a backup now and the database fails, it can be recovered only to the point before the cleared log file.