启用global_name：

SQL> show parameter global_name
NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
global_names                         boolean     FALSE
SQL> alter system set global_names=true scope=both;
System altered.
SQL> show parameter global_name
NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
global_names                         boolean     TRUE

修改global_name：

SQL> select * from global_name;
GLOBAL_NAME
--------------------------------------------------------------------------------
ORCL.REGRESS.RDBMS.DEV.US.ORACLE.COM
SQL> alter database rename global_name to orcl.com
2  ;
Database altered.
SQL> select * from global_name;
GLOBAL_NAME
--------------------------------------------------------------------------------
ORCL.COM