Rename the Amazon RDS master username
Changing the password is easily done through the console. Is there any way to change the master username after creation on RDS for PostgreSQL? If so, how?
Answer
You can't change username. You can check the following links that describe how to change master password and if Amazon adds the ability to change username you will find there:
Try to find at AWS CLI for RDS:
modify-db-instance --db-instance-identifier <value> --master-user-password (string)
--master-user-password (string)
The new password for the DB instance master user. Can be any printable ASCII character except "/", """, or "@".
Changing this parameter does not result in an outage and the change is asynchronously applied as soon as possible. Between the time of the request and the completion of the request, the MasterUserPassword element exists in the PendingModifiedValues element of the operation response. Default: Uses existing setting
Constraints: Must be 8 to 41 alphanumeric characters (MySQL, MariaDB, and Amazon Aurora), 8 to 30 alphanumeric characters (Oracle), or 8 to 128 alphanumeric characters (SQL Server).
The Amazon RDS Command Line Interface (CLI) has been deprecated. Instead, use the AWS CLI for RDS.
Via the AWS Management Console, choose the instance you need to reset the password for, click ‘Modify’ then choose a new master password.
If you don’t want to use the AWS Console, you can use the rds-modify-db-instance command (as per Amazon’s documentation for RDS) to reset it directly, given the AWS command line tools: rds-modify-db-instance instance-name --master-user-password examplepassword