------- 修改数据库db_name的方法 

SQL>  startup mount 

ORACLE instance started.

Total System Global Area  413372416 bytes

Fixed Size    2213896 bytes

Variable Size  335546360 bytes

Database Buffers   71303168 bytes

Redo Buffers    4308992 bytes

Database mounted.

SQL> quit

Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production

With the Partitioning, Oracle Label Security, OLAP, Data Mining,

Oracle Database Vault and Real Application Testing options

[oracle@OEL6 dbs]$ nid target=sys/yuanlei@orcl2 dbname=orcl

DBNEWID: Release 11.2.0.1.0 - Production on Tue Aug 19 22:22:39 2014

Copyright (c) 1982, 2009, Oracle and/or its affiliates.  All rights reserved.

Connected to database ORCL2 (DBID=836865814)

Connected to server version 11.2.0

Control Files in database:

    /u01/app/oracle/oradata/orcl2/control01.ctl

    /u01/app/oracle/oradata/orcl2/control02.ctl

Change database ID and database name ORCL2 to ORCL? (Y/[N]) => y

Proceeding with operation

Changing database ID from 836865814 to 1383851439

Changing database name from ORCL2 to ORCL

    Control File /u01/app/oracle/oradata/orcl2/control01.ctl - modified

    Control File /u01/app/oracle/oradata/orcl2/control02.ctl - modified

    Datafile /u01/app/oracle/oradata/orcl2/system01.db - dbid changed, wrote new name

    Datafile /u01/app/oracle/oradata/orcl2/sysaux01.db - dbid changed, wrote new name

    Datafile /u01/app/oracle/oradata/orcl2/undotbs01.db - dbid changed, wrote new name

    Datafile /u01/app/oracle/oradata/orcl2/users01.db - dbid changed, wrote new name

    Datafile /u01/app/oracle/oradata/orcl2/example01.db - dbid changed, wrote new name

    Datafile /u01/app/oracle/oradata/orcl2/tbs_yl01.db - dbid changed, wrote new name

    Datafile /u01/app/oracle/oradata/orcl2/tbs_yl02.db - dbid changed, wrote new name

    Datafile /u01/app/oracle/oradata/orcl2/tbs_yl03.db - dbid changed, wrote new name

    Datafile /u01/app/oracle/oradata/orcl2/tbs_yl04.db - dbid changed, wrote new name

    Datafile /u01/app/oracle/oradata/orcl2/tbs_yl05.db - dbid changed, wrote new name

    Datafile /u01/app/oracle/oradata/orcl2/tbs_yl06.db - dbid changed, wrote new name

    Datafile /u01/app/oracle/oradata/orcl2/tbs_yl07.db - dbid changed, wrote new name

    Datafile /u01/app/oracle/oradata/orcl2/tbs_yl08.db - dbid changed, wrote new name

    Datafile /u01/app/oracle/oradata/orcl2/rcatalog.db - dbid changed, wrote new name

    Datafile /u01/app/oracle/oradata/orcl2/temp01.db - dbid changed, wrote new name

    Control File /u01/app/oracle/oradata/orcl2/control01.ctl - dbid changed, wrote new name

    Control File /u01/app/oracle/oradata/orcl2/control02.ctl - dbid changed, wrote new name

    Instance shut down

Database name changed to ORCL.

Modify parameter file and generate a new password file before restarting.

Database ID for database ORCL changed to 1383851439.

All previous backups and archived redo logs for this database are unusable.

Database has been shutdown, open database with RESETLOGS option.

Succesfully changed database name and ID.

DBNEWID - Completed succesfully.