SQL> select userenv('language') from dual;

USERENV('LANGUAGE')
----------------------------------------------------
AMERICAN_AMERICA.WE8ISO8859P1

SQL> select userenv('language') from dual;

USERENV('LANGUAGE')
----------------------------------------------------
AMERICAN_AMERICA.WE8ISO8859P1

SQL> shutdown immetiate;
SP2-0717: illegal SHUTDOWN option
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area 1828716544 bytes
Fixed Size 2021536 bytes
Variable Size 419432288 bytes
Database Buffers 1392508928 bytes
Redo Buffers 14753792 bytes
Database mounted.
SQL> alter system enable restricted session;

System altered.

SQL> alter system set job_queue_processes=0;

System altered.

SQL> alter system set aq_tm_processes=0;

System altered.

SQL> alter database open;

Database altered.

SQL> alter database character set internal_use AL32UTF8;

Database altered.

SQL> select userenv('language') from dual;

USERENV('LANGUAGE')
----------------------------------------------------
AMERICAN_AMERICA.AL32UTF8

SQL> select userenv('language') from dual;

USERENV('LANGUAGE')
----------------------------------------------------
AMERICAN_AMERICA.AL32UTF8

SQL> shutdown immetiate;
SP2-0717: illegal SHUTDOWN option
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup;
ORACLE instance started.

Total System Global Area 1828716544 bytes
Fixed Size 2021536 bytes
Variable Size 419432288 bytes
Database Buffers 1392508928 bytes
Redo Buffers 14753792 bytes
Database mounted.
Database opened.
SQL> select userenv('language') from dual;

USERENV('LANGUAGE')
----------------------------------------------------
AMERICAN_AMERICA.AL32UTF8