When you create DB instances, your password strength is checked. You can modify the password strength as user root. For security reasons, you are advised to use a password that is at least as strong as the default one.
To provide O&M services, the system automatically creates system accounts when you create DB instances. These system accounts are unavailable to you.
Deleting, renaming, and changing passwords or permissions for these accounts will cause the DB instance to run abnormally. Exercise caution when performing these operations.