Changing database name and DBID in Oracle

After restoring production database to test for UAT or dev purposes, we may need to change the database name as well as DBID. When DBID is maintained unique, RMAN backup can be triggered for the restored database if we use recovery catalog. Let us see how to change both database name
and the DBID. You can opt to change just the database name.

First let us see the name and the DBID as below:

SQL> select name,dbid from v$database;

NAME            DBID
--------- ----------
PRDIMP  47133164

To change the database name and the DBID, ensure that the database is in mounted state:

SQL> select open_mode from v$database;

OPEN_MODE
--------------------
MOUNTED

The tool 'nid' helps us change both name and DBID. Let us see the parameters of nid as below:

[oracle@myserver ~]$ nid

DBNEWID: Release 11.2.0.4.0 - Production on Wed Aug 26 12:59:19 2015

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

Keyword     Description                    (Default)

----------------------------------------------------

TARGET      Username/Password              (NONE)

DBNAME      New database name              (NONE)

LOGFILE     Output Log                     (NONE)

REVERT      Revert failed change           NO

SETNAME     Set a new database name only   NO

APPEND      Append to output log           NO

HELP        Displays these messages        NO

As shown above, DBNAME accepts the new database name. If you make the SETNAME parameter to YES, only the database name will get changed. 

Execute the below to change the name only:

[oracle@myserver ~]$ nid TARGET=sys/ DBNAME=TSTIMP SETNAME='YES' LOGFILE=nid.log  

Execute the below to change the name and DBID:

[oracle@myserver ~]$ nid TARGET=sys/ DBNAME=TSTIMP SETNAME='NO' LOGFILE=nid.log  

This takes a few seconds to change the name. The log file can be located at the current working directory. 

After executing the above command, ensure that you copy your parameter file to reflect the new name as below:

[oracle@myserver dbs]$ cp initPRDIMP.ora initTSTIMP.ora

And change db_name in your parameter file. If it is a clustered setup, add instance_name as well. Once the change is made, startup the database using resetlogs if you opted to change both. If you just changed the name, you don't have to open using reset logs. 

SQL> alter database open resetlogs;

Database altered.

SQL> select name,dbid from v$database;

NAME            DBID

--------- ----------

TSTIMP  2323285955

Both got changed as executed the second command.

Now you can make entries in your /etc/oratab file to reflect your changed database name.

This is how we change the database name and the DBID using nid utility.

A word of caution: If you change the DBID of a database, all the backups and archive logs become unusable!