When I try to create a user without the c## prefix I get the ORA-65096 error:
$ sqlplus / as sysdba SQL*Plus: Release 12.1.0.2.0 Production on Sat May 16 07:44:23 2020 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, Real Application Clusters, Automatic Storage Management, OLAP, Advanced Analytics and Real Application Testing options SQL> create user ADMDADOS identified by ADMDADOS container=all; create user ADMDADOS identified by ADMDADOS container=all * ERROR at line 1: ORA-65096: invalid common user or role name
If you wish to create common user under CDB$ROOT than create user start with C## and c##:
ORA-65096: invalid common user or role name
Cause: An attempt was made to create a common user or role with a name that was not valid for common users or roles. In addition to the usual rules for user and role names, common user and role names must start with C## or c## and consist only of ASCII characters.
Action: Specify a valid common user or role name.
Solution:
Note: To change any hidden parameter always consult Oracle support!
SQL> alter session set "_ORACLE_SCRIPT"=true; Session altered. SQL> create user ADMDADOS identified by ADMDADOS container=all; User created. SQL> col username for a30 SQL> set lines 180 SQL> select username,common from dba_users where username='ADMDADOS'; USERNAME COM -------------------- --- ADMDADOS YES