Best way to design organization-specific models in Django?

Question

This is a database model design question. Let's say I'm designing an app like Slack. Slack has multiple Organizations, and within each Organization there are objects that only should be accessed by that Organization (eg. its chat records, files, etc.). What is the best way to set up these per-Organization objects in Django?

A simple solution is to attach a ForeignKey to every one of these objects. Like so:

class Organization(models.Model):
    # ...

class File(models.Model):
    organization = models.ForeignKey(
        'Organization',
        on_delete=models.CASCADE,
    )
    # ...

class ChatThread(models.Model):
    organization = models.ForeignKey(
        'Organization',
        on_delete=models.CASCADE,
    )
    # ...

But if we do it like this, we need to put an index on organization, and since there are many such per-Organization objects, it seems a little wasteful.

Is there a cleaner way to design this?

Answer 1

I think your method is about as good as it would need to be. In terms of indexing the organization column, you can use db_index=False to disable the creation of an index.

If you want to abstract the organization field and have some methods available on all organization objects, you could use an abstract model like so:

class Organization(models.Model):
    # ...

class OrganizationModel(models.Model):
    organization = models.ForeignKey(
        'Organization',
        on_delete=models.CASCADE,
        db_index=False,
    )

    class Meta:
        abstract = True

class File(OrganizationModel):
    # ...

class ChatThread(OrganizationModel):
    # ...