Django easy_thumbnails reduce database queries

Question

I am profiling a django app with django debug toolbar. I want to reduce the number of database queries from view and rendering.

For each easy_thumbnail template tag, e.g.

{% thumbnail coop.logo 250x250 %}

there seem to be two database calls:

SELECT ••• FROM "easy_thumbnails_source" WHERE ("easy_thumbnails_source"."name" = 'partner-logo/151119_Airlines_Logo_PNG.png' AND "easy_thumbnails_source"."storage_hash" = 'c536f7b8a65dd208e93ec823d3bce653')
  Duplicated 36 times.  


SELECT ••• FROM "easy_thumbnails_thumbnail" WHERE ("easy_thumbnails_thumbnail"."name" = 'partner-logo/151119_Airlines_Logo_PNG.png.250x250_q85.jpg' AND "easy_thumbnails_thumbnail"."source_id" = 1525 AND "easy_thumbnails_thumbnail"."storage_hash" = '5e4fc44a8986f46175c0675df42cf544')
  Duplicated 38 times.

a) Why two calls? Can this be reduced? b) Why are they duplicated so many times? Is this costing me performance?

Edit:

model.py
class Cooperation(models.Model):
  ...
  logo = models.ImageField(upload_to='partner-logo/', null=True, blank=True)
  ...


Traces:
table source:
/projects/primomedico.new/frontend/views.py in home(646)
  return render(request, 'home.html', context)
/projects/primomedico.new/.venv/lib/python3.5/site-packages/easy_thumbnails/templatetags/thumbnail.py in render(116)
  thumbnail = get_thumbnailer(source).get_thumbnail(opts)
/projects/primomedico.new/.venv/lib/python3.5/site-packages/easy_thumbnails/files.py in get_thumbnail(512)
  thumbnail = self.get_existing_thumbnail(thumbnail_options)
/projects/primomedico.new/.venv/lib/python3.5/site-packages/easy_thumbnails/files.py in get_existing_thumbnail(478)
  exists = self.thumbnail_exists(filename)
/projects/primomedico.new/.venv/lib/python3.5/site-packages/easy_thumbnails/files.py in thumbnail_exists(593)
  source = self.get_source_cache()
/projects/primomedico.new/.venv/lib/python3.5/site-packages/easy_thumbnails/files.py in get_source_cache(628)
  check_cache_miss=self.thumbnail_check_cache_miss)
/projects/primomedico.new/.venv/lib/python3.5/site-packages/easy_thumbnails/models.py in get_file(26)
  obj = manager.get(**kwargs)

table thumbnail:
/projects/primomedico.new/frontend/views.py in home(646)
  return render(request, 'home.html', context)
/projects/primomedico.new/.venv/lib/python3.5/site-packages/easy_thumbnails/templatetags/thumbnail.py in render(116)
  thumbnail = get_thumbnailer(source).get_thumbnail(opts)
/projects/primomedico.new/.venv/lib/python3.5/site-packages/easy_thumbnails/files.py in get_thumbnail(512)
  thumbnail = self.get_existing_thumbnail(thumbnail_options)
/projects/primomedico.new/.venv/lib/python3.5/site-packages/easy_thumbnails/files.py in get_existing_thumbnail(478)
  exists = self.thumbnail_exists(filename)
/projects/primomedico.new/.venv/lib/python3.5/site-packages/easy_thumbnails/files.py in thumbnail_exists(609)
  thumbnail = self.get_thumbnail_cache(thumbnail_name)
/projects/primomedico.new/.venv/lib/python3.5/site-packages/easy_thumbnails/files.py in get_thumbnail_cache(639)
  check_cache_miss=self.thumbnail_check_cache_miss)
/projects/primomedico.new/.venv/lib/python3.5/site-packages/easy_thumbnails/models.py in get_file(26)
  obj = manager.get(**kwargs)