Setting ORACLE DB into noarchivelog mode

Steps when the database state is down:
1. Login to sqlplus
  - sqlplus /nolog
  - connect / as sysdba
2. The db must be mounted EXCLUSIVE and not open for operation
  - startup mount;
3. Check the log mode status of the database
  - select log_mode from v$database;
4. Setting it to noarchivelog mode
  - alter database noarchivelog;
5. Setting db open for user operation
  - alter database open;
6. Reverting back to archivelog mode
  - alter database archivelog;