Large Table Paginator for Django Admin (Accompanying blog: https://medium.com/squad-engineering/estimated-counts-for-faster-django-admin-change-list-963cbf43683e)

admin.py

from django.contrib.admin import ModelAdmin

class MyTableAdmin(ModelAdmin):
    ...
    paginator = LargeTablePaginator
    ...
    

paginator.py

from django.core.paginator import Paginator


class LargeTablePaginator(Paginator):
    """
    Warning: Postgresql only hack

    Overrides the count method of QuerySet objects to get an estimate instead of actual count when not filtered.
    However, this estimate can be stale and hence not fit for situations where the count of objects actually matter.
    """
    def _get_count(self):
        if getattr(self, '_count', None) is not None:
            return self._count
        
        query = self.object_list.query
        if not query.where:
            try:
                cursor = connection.cursor()
                cursor.execute("SELECT reltuples FROM pg_class WHERE relname = %s",
                               [query.model._meta.db_table])
                self._count = int(cursor.fetchone()[0])
            except:
                self._count = super(LargeTablePaginator, self)._get_count()
        else:
            self._count = super(LargeTablePaginator, self)._get_count()
            
        return self._count

    count = property(_get_count)