How to change database log mode to archiving mode

After connect to the database via SQLPLUS. Shutdown the database using the NORMAL, IMMEDIATE, or TRANSACTIONAL option.

SQL> select * from v$version;

BANNER                                                                               CON_ID
-------------------------------------------------------------------------------- ----------
Oracle Database 12c Standard Edition Release 12.2.0.1.0 - 64bit Production                0
PL/SQL Release 12.2.0.1.0 - Production                                                    0
CORE    12.2.0.1.0      Production                                                                0
TNS for Linux: Version 12.2.0.1.0 - Production                                            0
NLSRTL Version 12.2.0.1.0 - Production                                                    0

SQL> archive log list
Database log mode              No Archive Mode
Automatic archival             Disabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     129
Current log sequence           131

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.

We can start the database with mount mode.

SQL> startup mount
ORACLE instance started.

Total System Global Area 6375342080 bytes
Fixed Size                  8634896 bytes
Variable Size            1375735280 bytes
Database Buffers         4982833152 bytes
Redo Buffers                8138752 bytes
Database mounted.

Now, we can alter the database to archive log mode, then open the database. As it can be seen from the following command, current log mode is archive mode.

SQL> alter database archivelog;

Database altered.

SQL> alter database open;

Database altered.

SQL> archive log list
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     129
Next log sequence to archive   131
Current log sequence           131