How about this. You'll find more on the oracle metalink. I've used this
method before and it works fine.
Document ID: 106373.655
Title: Changing dbname or ORACLE_SID
Creation Date: 07 September 1994
Last Revision Date: 07 September 1994
Revision Number: 0
Product Version: 7
Information Type: ADVISORY
Abstract: This bulletin describes how to change the dbname for a
database, or the ORACLE_SID for an instance, without
having to recreate the database.
Modifying a database to run under a new ORACLE_SID
1. Shutdown instance
2. Backup all control, redo and data files.
3. Go thru the .profile, .cshrc, .login, oratab, tnsnames.ora(for net v2),
and redefine the environment variable ORACLE_SID to a new value.
ie search thru disks and do a grep ORACLE_SID *
4. cd $ORACLE_HOME/dbs and rename the following files:
o init<sid>.ora (or use pfile to point to the init file.)
o control file(s) This is optional if you don't rename any of the
controlfiles, and the control_files parameter is
used. control_files would be set in the initSID.ora
file or in a file it references with the ifile
parameter. Make sure control_files doesn't point to
any old file names, if you renamed them.
o crdb<sid>.sql & crdb2<sid>.sql This is optional. These are
only used at database creation.
5. cd $ORACLE_HOME/rdbms/admin and rename the file:
o startup<sid>.sql This is optional.
(On some platforms, this file may be in $ORACLE_HOME/rdbms/install.)
Make sure the contents of this file do not reference old initSID.ora
files that have been renamed. This file simplifies the process to
"startup exclusive" your database.
6. To rename the database files and redo log files, you would follow the
instructions in the bulletin: 98863.723.
7. Change the ORACLE_SID environment variable to the new value.
8. start up database and verify it works. Once you have done this,
the database and take a final backup of all control, redo and data
9. When the instance is started, the control file gets updated with the
Changing the dbname for a database
2. connect internal
3. alter database backup controlfile to trace;
This will write in a trace file, the CREATE CONTROLFILE command that
would recreate the controlfile as it currently exists.
4. Exit and go to the directory where your trace files are located.
They are usually in the $ORACLE_HOME/rdbms/log directory.
If user_dump_dest is set in the initSID.ora, then go to the directory
listed in the user_dump_dest variable.
The trace file will have the form "ora_NNNN.trc with NNNN being a
5. Get the CREATE CONTROLFILE command from the trace file and put it in a
new file called something like ccf.sql.
6. Edit the ccf.sql file and modify the CREATE CONTROLFILE command.
Just change the word "REUSE" to "SET",and "NORESETLOGS" to
and modify the dbname.
CREATE CONTROLFILE REUSE DATABASE "olddbname" NORESETLOGS ...
CREATE CONTROLFILE set DATABASE "newdbname" RESETLOGS ...
Then save the ccf.sql file.
7. Rename the old control files for backup purposes and so they are not
the way of creating the new ones.
8. Edit initSID.ora so that db_name="newdbname".
10. connect internal
11. startup nomount
13. alter database open;
14. Make sure the database is working. Shutdown and backup the database.
ORACLE7 SERVER, SQL Language Reference Manual
Oracle Worldwide Customer Support
> I had posted this a while back and just wanted to see if anyone has had
> the same problem.
> I have multiple database instances which I copy/clone into other
> database instances on the same machine. I basically copy the datafiles
> from one database and then run a create controlfile script which I
> extract from the source database. Although I would prefer doing it a
> cleaner way (export/import) the time it takes (5-6 hours) for that vs.
> the cloning method (10-20min) does not make it feasible.
> The problem is that because I am using a straight datafile copy the
> clone is really a clone of the original, and in Oracle 8 the dbid is not
> reset which means I can't use rman because rman cannot handle having
> multiple database instances with the same dbid.
> Is there any way to manually change the dbid? Is that OK or will oracle
> chase me down and beat me in the streets as a example of what not to do?
> Any help with this is greatly appreciated,
> Glen Upreti
> Glen Upreti
> Senior Oracle DBA
> Northern Arizona University
> Phone (520)523-8393 Fax(520)523-7407