Enabling Archive Log Mode

Whenever your database crashes, the only way to recover it is using the archive log files. Your database must be in achieve mode to recover. With this article, I will show you how to enable and check the the log mode?

Only a disabled archive log mode can be enabled.  Before enabling it lets see how you can check the mode of Archive log? There are various ways you can the mode. You are free to use any of  the listed below Oracle SQL  statements.

1. select log_move from v$database;
2. archive log list;

Before:

Database log mode              No Archive Mode
Automatic archival             Disabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     100
Current log sequence           101

Now you have confirmed your Oracle Instance archive log mode is disabled. Use  the instructions below to enable it.

1. Shutdown;  
2. Startup mount;
3. Alter database archivelog;
4. alter database open;
5. select log_mode from v$database;
6. show parameter db_recovery_file_dest

After:

Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     100
Next log sequence to archive   101
Current log sequence           101

Hope it worked for you!