NLS_CHARACTERSET Change Oracle

 [oracle@OC-APP ~]$ sqlplus  / as sysdba

SQL*Plus: Release 12.1.0.2.0 Production on Sun Feb 27 17:27:30 2022

Copyright (c) 1982, 2014, Oracle.  All rights reserved.

Connected to:

Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production

With the Partitioning, OLAP, Advanced Analytics and Real Application Testing opt                                                                                        ions

SQL>

SQL>

SQL> SELECT value AS db_charset FROM nls_database_parameters WHERE parameter = 'NLS_CHARACTERSET';

DB_CHARSET

----------------------------------------------------------------

WE8MSWIN1252

SQL>

SQL>

SQL>

SQL> shutdown immediate

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> exit

Disconnected from Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production

With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options

[oracle@OC-APP ~]$

[oracle@OC-APP ~]$ sqlplus / as sysdba

SQL*Plus: Release 12.1.0.2.0 Production on Sun Feb 27 17:31:51 2022

Copyright (c) 1982, 2014, Oracle.  All rights reserved.

Connected to an idle instance.

SQL>

SQL> startup mount;

ORACLE instance started.

Total System Global Area 1.0066E+10 bytes

Fixed Size                  3721176 bytes

Variable Size            1778386984 bytes

Database Buffers         8254390272 bytes

Redo Buffers               29831168 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 AL32UTF8;

ALTER DATABASE CHARACTER SET AL32UTF8

*

ERROR at line 1:

ORA-12712: new character set must be a superset of old character set

SQL> ALTER DATABASE CHARACTER SET INTERNAL_USE AL32UTF8;

Database altered.

SQL> shutdown immediate

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> startup

ORACLE instance started.

Total System Global Area 1.0066E+10 bytes

Fixed Size                  3721176 bytes

Variable Size            1778386984 bytes

Database Buffers         8254390272 bytes

Redo Buffers               29831168 bytes

Database mounted.

Database opened.

SQL>

SQL>

SQL>

SQL> SELECT value AS db_charset FROM nls_database_parameters WHERE parameter = 'NLS_CHARACTERSET';

DB_CHARSET

--------------------------------------------------------------------------------

AL32UTF8

SQL>