Question

Suppose we have multiple sites (using sites-framework of Django) running on the same django instance.

MyModel.objects.filter(site_id=request.site, slug=slug)[0] might be an overhead in the future. So I was wondering if I could split the databases for this model(s) for querying faster.

So if request.site is 1, running

MyModel.objects.get(slug=slug)

will query only db1.

If request.site is 2, running

MyModel.objects.get(slug=slug)

will query only db2.

I will be getting request.site from the request parameter of the view as value of site will be dynamically determined according to the subdomain used: de, fr, etc.

Answer 1

You may create a custom router to do this:

Example:

def get_current_site():
   SITE_ID = getattr(settings, 'SITE_ID', 1)
   site_name = Site.objects.get(id=SITE_ID)
   return site_name


DATABASE_ROUTERS = ['CustomDatabaseRouter',] #a setting that Django understands.

class CustomDatabaseRouter(object):

  def db_for_read(self, model, **hints):
     site_name = get_current_site()
     if site_name  in ['site1']:
         return 'db1'
     if site_name in ['site2']:
        return 'db2'
     return 'default'

  def db_for_write(self, model, **hints):
     site_name = get_current_site()
     if site_name  in ['site1']:
         return 'db1'
     if site_name in ['site2']:
        return 'db2'
     return 'default'

  def allow_syncdb(self, model, **hints):
     site_name = get_current_site()
     if site_name in ['site1'] and db == 'db1':
         return True
     if site_name in ['site2'] and db == 'db2':
        return True
     return False

You can readup more here
https://docs.djangoproject.com/en/dev/topics/db/multi-db/