enable pluggable database(PDB) archivelog mode

Enabling archive log mode -12c pluggable database/Container database.

Since the Redologs are created at container database level in 12c and not at pluggable database level.
(Enabling archivelog at pluggable database level is not possible). Archiving is done at CDB's.

You can check archive log mode either by querying v$database or archivelog list

SQL> select name,open_mode,log_mode from v$database;

NAME      OPEN_MODE            LOG_MODE
--------- -------------------- ------------
CDB      READ WRITE           NOARCHIVELOG

(OR)

SQL> archive log list
Database log mode        Archive Mode
Automatic archival        Disabled
Archive destination        USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     11
Next log sequence to archive   13
Current log sequence        13

***************  ***************
To enable the Archive-log mode
***************  ***************

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

SQL> startup mount;
ORACLE instance started.

Total System Global Area  788529152 bytes
Fixed Size      2929352 bytes
Variable Size    541068600 bytes
Database Buffers   239075328 bytes
Redo Buffers      5455872 bytes
Database mounted.

SQL> ALTER DATABASE ARCHIVELOG;

Database altered.

SQL> ALTER DATABASE OPEN;

Database altered.

SQL> select name,open_mode,log_mode from v$database;

NAME      OPEN_MODE            LOG_MODE
--------- -------------------- ------------
CDB      READ WRITE           ARCHIVELOG



SQL> archive log list
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     413
Next log sequence to archive   415
Current log sequence           415

SQL> show parameter DB_RECOVERY_FILE_DEST

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest                string      /u03/app/oracle/fast_recovery_area
db_recovery_file_dest_size           big integer 27G