Restricted database user for Django
For storing the credentials to the privileged user for management commands, when running manage.py you can use the --settings flag, which you would point to another settings file that has the other database credentials.
Example migrate command using the new settings file:
python manage.py migrate --settings=myapp.privileged_settings
I'm running Django with Postgres database. On top of application-level security checks, I'm considering adding database-level restrictions. E.g. the application code should only be able to INSERT into log tables, and not UPDATE or DELETE from them. 
I would manually create database user with appropriate grants for this. I would also need a more powerful user for running database migrations.
My question is, do people practice things like this? Any advice, best practices on using restricted database users with Django? 
Edit: To clarify, there's no technical problem, I'm just interested to hear other people's experiences and takeaways. One Django-specific thing is, I'll need at least two DB users: for normal operation and for running migrations. Where do I store credentials for the more privileged user? Maybe make manage.py migrate prompt for password? 
As for the reasoning, suppose my app has a SQL injection vulnerability. With privileged user, the attacker can do things like drop all tables. With a more limited user there's slightly less damage potential and afterwards there's some evidence in insert-only log tables.