I understand the need to have the schema where it's being used but if you ever need to make modifications like custom fields (say an email field) then your sche

I understand the need to have the schema where it's being used but if you ever need to make modifications like custom fields (say an email field) then your schema isn't just stored in the DB any more. With Django your custom field declarations live in the same place as more mundane fields. If you port that models file to another machine and run syncdb you are going to be left with the same schema with the same restrictions.