Converting the DB to archive Log and Non Archive Log Mode

Archivelog is necessary in recovery of full database and complete backup, Database can be converted to archive log as below:

SQL> archive log list;

Database log mode              No Archive Mode

Automatic archival             Disabled

Archive destination            /data/archive_sn

Oldest online log sequence     31

Current log sequence           33

SQL>

Change location of Archive Log List:

SQL> ALTER SYSTEM SET log_archive_dest_2='LOCATION=/u01/archivelog2' scope=both;

Enable Archive log mode

SQL> shutdown immediate;

SQL> startup mount;

SQL> alter database archivelog;

SQL> alter database open;

SQL> archive log list

Database log mode              Archive Mode

Automatic archival             Enabled

Archive destination            /data/archive_sn

Oldest online log sequence     31

Next log sequence to archive   33

Current log sequence           33

/************************ Converting Archive Log to Non Archive Log *******************/

Below are steps:

SQL> shutdown immediate;

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> startup mount;

ORACLE instance started.

Total System Global Area 1207959552 bytes

Fixed Size                  8620080 bytes

Variable Size             771753936 bytes

Database Buffers          419430400 bytes

Redo Buffers                8155136 bytes

Database mounted.

SQL> alter database noarchivelog;

Database altered.

SQL> alter database open;

Database altered.

SQL> archive log list;

Database log mode              No Archive Mode

Automatic archival             Disabled

Archive destination            /data/archive_sn

Oldest online log sequence     31

Current log sequence           33

SQL>