As I understand it, a ModelForm for a model with a unique field will query the database to do a uniqueness check in the validation step, outside of the database uniqueness enforcement. Is that accurate?
If so, is the reason for this to have all the validation in the form? Or are there other reasons to do the validation in the form and then have the database enforce uniqueness again?
Are there any concerns about race conditions, where a form validates properly, but then the save call fails because a duplicate record was inserted in the meantime?