如果配置了DBConsole，需要删除DBConsole对象。之后完全关闭，重新启动进行mount状态。同时，确认一下Oracle Net目录中三个文件：tnsnames.ora、listener.ora和sqlnet.ora，其中包括DBNAME项目，都需要修改。
[oracle@MYTElife bin]$ sqlplus /nolog
SQL*Plus: Release 11.2.0.4.0 Production on Wed Oct 19 18:45:58 2016
Copyright (c) 1982, 2013, Oracle. All rights reserved.
SQL> conn / as sysdba
Connected.
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount
ORACLE instance started.
Total System Global Area 3540881408 bytes
Fixed Size 2258320 bytes
Variable Size 855640688 bytes
Database Buffers 2667577344 bytes
Redo Buffers 15405056 bytes
Database mounted.
进入$ORACLE_HOME/bin文件夹，调用nid命令。
[oracle@MYTElife bin]$ nid target=sys/oracle dbname=testdb
DBNEWID: Release 11.2.0.4.0 - Production on Wed Oct 19 18:48:44 2016
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
Connected to database MYTEDB (DBID=2764682050)
Connected to server version 11.2.0
Control Files in database:
/u01/app/oracle/oradata/MYTEDB/controlfile/o1_mf_bw7762ov_.ctl
/u01/app/oracle/fast_recovery_area/MYTEDB/controlfile/o1_mf_bw7762v3_.ctl
Change database ID and database name MYTEDB to TESTDB? (Y/[N]) => y
Proceeding with operation
Changing database ID from 2764682050 to 2708979596
Changing database name from MYTEDB to TESTDB
Control File /u01/app/oracle/oradata/MYTEDB/controlfile/o1_mf_bw7762ov_.ctl - modified
Control File /u01/app/oracle/fast_recovery_area/MYTEDB/controlfile/o1_mf_bw7762v3_.ctl - modified
Datafile /u01/app/oracle/oradata/MYTEDB/datafile/o1_mf_system_bw773xok_.db - dbid changed, wrote new name
Datafile /u01/app/oracle/oradata/MYTEDB/datafile/o1_mf_sysaux_bw773xpr_.db - dbid changed, wrote new name
Datafile /u01/app/oracle/oradata/MYTEDB/datafile/o1_mf_undotbs1_bw773xqo_.db - dbid changed, wrote new name
Datafile /u01/app/oracle/oradata/MYTEDB/datafile/o1_mf_users_bw773xrv_.db - dbid changed, wrote new name
Datafile /u01/app/oracle/oradata/MYTEDB/datafile/o1_mf_MYTEdev_bw8xbqrz_.db - dbid changed, wrote new name
Datafile /u01/app/oracle/oradata/MYTEDB/datafile/o1_mf_inttestt_bw8xdnkt_.db - dbid changed, wrote new name
Datafile /u01/app/oracle/oradata/MYTEDB/datafile/o1_mf_epssite_by19vtnh_.db - dbid changed, wrote new name
Datafile /u01/app/oracle/oradata/MYTEDB/datafile/o1_mf_temp_bw776mow_.tm - dbid changed, wrote new name
Control File /u01/app/oracle/oradata/MYTEDB/controlfile/o1_mf_bw7762ov_.ctl - dbid changed, wrote new name
Control File /u01/app/oracle/fast_recovery_area/MYTEDB/controlfile/o1_mf_bw7762v3_.ctl - dbid changed, wrote new name
Instance shut down
Database name changed to TESTDB.
Modify parameter file and generate a new password file before restarting.
Database ID for database TESTDB changed to 2708979596.
All previous backups and archived redo logs for this database are unusable.
Database is not aware of previous backups and archived logs in Recovery Area.
Database has been shutdown, open database with RESETLOGS option.
Succesfully changed database name and ID.
DBNEWID - Completed succesfully.
在提示信息中，可以清晰看到Oracle NID名称将数据文件中的DBID和Name信息修改，并且在提示中提醒了需要修改内容。
在alert log中，我们看到了DBID和Name的变化过程。
Wed Oct 19 18:49:04 2016
*** DBNEWID utility started ***
DBID will be changed from 2764682050 to new DBID of 2708979596 for database MYTEDB
DBNAME will be changed from MYTEDB to new DBNAME of TESTDB
Starting datafile conversion
Datafile conversion complete
Database name changed to TESTDB.
Modify parameter file and generate a new password file before restarting.
Database ID for database TESTDB changed to 2708979596.
All previous backups and archived redo logs for this database are unusable.
Database has been shutdown, open with RESETLOGS option.
Succesfully changed database name and ID.
*** DBNEWID utility finished succesfully ***
下面，需要修改Spfile中的dbname信息。方法和以前用到的相同，都是通过spfile生成pfile，手工修改其中的db_name参数。
[oracle@MYTElife trace]$ sqlplus /nolog
SQL*Plus: Release 11.2.0.4.0 Production on Wed Oct 19 18:51:26 2016
Copyright (c) 1982, 2013, Oracle. All rights reserved.
SQL> conn / as sysdba
Connected to an idle instance.
SQL> create pfile from spfile;
File created.
修改生成initMYTEdb.ora文件。
[oracle@MYTElife trace]$ cd $ORACLE_HOME/dbs
[oracle@MYTElife dbs]$ ls -l
total 9544
-rw-r----- 1 oracle oinstall 1544 Oct 19 18:49 hc_MYTEdb.dat
-rw-r--r-- 1 oracle oinstall 2851 May 15 2009 init.ora
-rw-r--r-- 1 oracle oinstall 1092 Oct 19 18:51 initMYTEdb.ora
-rw-r----- 1 oracle oinstall 24 Aug 7 2015 lkMYTEDB
-
[oracle@MYTElife dbs]$ vi initMYTEdb.ora
MYTEdb.__large_pool_size=184549376
*.db_create_file_dest='/u01/app/oracle/oradata'
*.db_domain=''
*.db_name='testdb'
*.db_recovery_file_dest='/u01/app/oracle/fast_recovery_area'
*.db_recovery_file_dest_size=10737418240
如果使用ASM，还要修改ASM文件名。之后就可以使用新的testdb来启动。
[oracle@MYTElife dbs]$ export ORACLE_SID=testdb
[oracle@MYTElife dbs]$ sqlplus /nolog
SQL*Plus: Release 11.2.0.4.0 Production on Wed Oct 19 18:54:26 2016
Copyright (c) 1982, 2013, Oracle. All rights reserved.
SQL> conn / as sysdba
Connected to an idle instance.
SQL> startup mount pfile=initMYTEdb.ora
ORACLE instance started.
Total System Global Area 3540881408 bytes
Fixed Size 2258320 bytes
Variable Size 855640688 bytes
Database Buffers 2667577344 bytes
Redo Buffers 15405056 bytes
Database mounted.
Open数据库时候，由于是一个全新的DBID，所以需要resetlogs模式。在日志上，我们的确也看到了Oracle删除原有online redo log动作的过程。
SQL> alter database open resetlogs;
Database altered.
--alert log信息
Wed Oct 19 18:56:59 2016
alter database open resetlogs
RESETLOGS after complete recovery through change 1719246
Resetting resetlogs activation ID 2764689218 (0xa4c9cf42)
Deleted Oracle managed file /u01/app/oracle/oradata/MYTEDB/onlinelog/o1_mf_1_bw77672y_.log
Deleted Oracle managed file /u01/app/oracle/fast_recovery_area/MYTEDB/onlinelog/o1_mf_1_bw7767d4_.log
Deleted Oracle managed file /u01/app/oracle/oradata/MYTEDB/onlinelog/o1_mf_2_bw776938_.log
Deleted Oracle managed file /u01/app/oracle/fast_recovery_area/MYTEDB/onlinelog/o1_mf_2_bw7769cc_.log
Deleted Oracle managed file /u01/app/oracle/oradata/MYTEDB/onlinelog/o1_mf_3_bw776cck_.log
Deleted Oracle managed file /u01/app/oracle/fast_recovery_area/MYTEDB/onlinelog/o1_mf_3_bw776cmv_.log
Wed Oct 19 18:57:03 2016
Setting recovery target incarnation to 2
重新生成spfile。
SQL> create spfile from memory;
File created.
创建密码文件，对应新的testdb的数据库名称。
[oracle@MYTElife dbs]$ ls -l | grep orapw
-rw-r----- 1 oracle oinstall 1536 Aug 7 2015 orapwMYTEdb
[oracle@MYTElife dbs]$ orapwd file=orapwtestdb password=oracle entries=10 force=y
[oracle@MYTElife dbs]$ ls -l | grep orapw
-rw-r----- 1 oracle oinstall 1536 Aug 7 2015 orapwMYTEdb
-rw-r----- 1 oracle oinstall 2560 Oct 19 19:02 orapwtestdb
查看监听器状态，修改Oracle NET文件。
[oracle@MYTElife dbs]$ lsnrctl status
LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 19-OCT-2016 19:09:51
Copyright (c) 1991, 2013, Oracle. All rights reserved.
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
STATUS of the LISTENER
------------------------
Alias LISTENER
（篇幅原因，有省略……）
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=localhost)(PORT=1521)))
Services Summary...
Service "testdb" has 1 instance(s).
Instance "testdb", status READY, has 1 handler(s) for this service...
Service "testdbXDB" has 1 instance(s).
Instance "testdb", status READY, has 1 handler(s) for this service...
The command completed successfully
对应新生成的dbid和dbname信息。
SQL> select dbid, name from v$database;
DBID NAME
---------- ---------
2708979596 TESTDB
最后，如果使用了global_name参数，也要进行修改。
注意：如果是Windows环境的话，DBNAME修改，在Services列表中需要重新生成服务。另外，修改DBID之后，原有的所有备份都失效了，需要重新备份。