一、修改PDB的global_name

SYS@orcl1>sho pdbsCON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------2 PDB$SEED                       READ ONLY  NO3 PDB                            READ WRITE NO
SYS@orcl1>alter session set container=pdb;Session altered.SYS@orcl1>select * from global_name;GLOBAL_NAME
---------------------------------------------------------------------------------------------------------------------------
PDB.CN.OSC.ORACLE.COMSYS@orcl1>sho pdbsCON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------3 PDB                            READ WRITE NO
SYS@orcl1>       
SYS@orcl1>sho parameter domainNAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_domain                            string      cn.osc.oracle.com
SYS@orcl1>
SYS@orcl1>UPDATE GLOBAL_NAME SET GLOBAL_NAME='orcl';1 row updated.SYS@orcl1>commit;Commit complete.SYS@orcl1>select * from global_name;GLOBAL_NAME
---------------------------------------------------------------------------------------------------------------------------
orcl

cdb信息确认：

SYS@orcl1>alter session set container=cdb$root;Session altered.SYS@orcl1>sho pdbsCON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------2 PDB$SEED                       READ ONLY  NO3 PDB                            READ WRITE NO--- there is nothing change for cdb
SYS@orcl1>select * from global_name;GLOBAL_NAME
---------------------------------------------------------------------------------------------------------------------------
ORCL.CN.OSC.ORACLE.COM

二、重启数据库实例

#grid
srvctl stop database -o immediate -d orcl
srvctl start database -d orcl

测试：
创建dblink后，查询字典表dba_db_links来确认dblink名称是否可以创建为不带域名的。

三、修改domain后重试

如以上未成功可尝试此操作

#首先show parameter domain看参数值，需要设为null
alter system set db_domain='' scope=spfile sid='*';
#重启数据库实例