Redo log files are not multiplexed in your database. Redo log blocks are corrupted in group 2, and archiving has stopped. All the redo logs are filled and database activity is halted. Database…

RECOVER LOGFILE BLOCK is not a valid Oracle SQL command; Oracle does not provide a built-in mechanism for block-level repair of online redo log files through this syntax.

ALTER DATABASE DROP LOGFILE GROUP 2 will be rejected because Oracle will not drop a log group that has not been successfully archived, and dropping it would not repair the archiving stoppage.

ALTER DATABASE CLEAR LOGFILE GROUP 2 without the UNARCHIVED keyword will fail because Oracle refuses to clear a redo log group that has not yet been archived, to prevent silent data loss.

ALTER DATABASE RECOVER LOGFILE is not a valid Oracle SQL command; the RECOVER clause in ALTER DATABASE applies to datafiles and tablespaces, not online redo log files.

ALTER DATABASE CLEAR UNARCHIVED LOGFILE GROUP 2 reinitializes the corrupted log group even though it was never archived, explicitly acknowledging that the redo in that group will be lost. This command is the designated solution when archiving has stalled due to log corruption and all online redo log groups are full, allowing the ARCH process to resume. After executing this command a full backup is mandatory because media recovery relying on logs prior to the cleared group is no longer possible.