Oracle Database SID convert from uppercase to lowercase

Converting a database SID from uppercase to lowercase in the Oracle database can be needed sometimes.
Below are general steps for converting a database SID from uppercase to lowercase for a few popular DBMS:

Oracle:

Shut down the database using the “shutdown immediate” command
Start the database in “mount” mode using the “startup mount” command
Change the SID to lowercase using the “alter system set db_name=’new_sid’ scope=spfile;” command, where “new_sid” is the desired lowercase SID
Restart the database using the “alter database open” command

Below are the commands that we executed to change from uppercase to lowercase.

1) CHANGE DB_NAME TO SOME TEMP NAME FIRST

We are changing to a different name first as Oracle will not allow keeping the same name (even lowercase).

SQL> SHUTDOWN IMMEDIATE
SQL> STARTUP MOUNT
$ nid TARGET=SYS/<syspass> DBNAME='tempname' SETNAME=YES
SQL> STARTUP NOMOUNT
SQL> ALTER SYSTEM SET DB_NAME='tempname' SCOPE=SPFILE;
SQL> SHUTDOWN IMMEDIATE
SQL> STARTUP MOUNT
SQL> ALTER DATABASE OPEN RESETLOGS; or ALTER DATABASE OPEN;

2) NOW CHANGE THE DB_NAME TO THE REQUIRED LOWER CASE dbname

SQL> SHUTDOWN IMMEDIATE
SQL> STARTUP MOUNT
$ nid TARGET=SYS/<syspass> DBNAME='dbname' SETNAME=YES
SQL> STARTUP NOMOUNT
SQL> ALTER SYSTEM SET DB_NAME='dbname' SCOPE=SPFILE;
SQL> SHUTDOWN IMMEDIATE
SQL> STARTUP MOUNT
SQL> ALTER DATABASE OPEN RESETLOGS; or ALTER DATABASE OPEN;

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Brijesh Gogia

I’m an experienced Cloud and AI Architect with over 19 years in Oracle Applications, Databases, and Cloud ecosystems. My work spans large-scale, global projects where I’ve designed and optimized solutions across both Oracle and non-Oracle stacks—on-prem and in the cloud. Lately, my focus has shifted toward integrating AI into enterprise architectures, leveraging GenAI, automation, and data intelligence to drive performance, resilience, and modernization. I’m passionate about exploring emerging AI tools, agentic workflows, and practical use cases—and I'm fortunate that my role gives me space to experiment and share my learnings.

Oracle Database SID convert from uppercase to lowercase

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