In Django 1.6 - how to use a pre-existing database for unit tests? (--keepdb flag)

We are using Django 1.6.x for our codebase and there are no unit tests for the code.

I want to begin to implement unit tests on the codebase and we have a Oracle database we can use for the task. On other codebases we maintain, I can use the --keepdb flag to prevent django from creating/tearing down the database.

Apparently in earlier versions of Django this flag doesn't exist.

Created a custom settings file but I cannot figure out how to prevent the modification of db tables I do not have permissions for.