The goal is to reduce the number of query created to retrieve the
presentation of the the cache objects associated with the Result
objects.

Use list comprehension and sets.

Replaced map/filters combo with list comprehension and
exploit Django's ORM features like values_list to generate
all these lists.

Replaced map/filters combo with list comprehension and
exploit Django's ORM features like values_list to generate
all these lists.

Replaced filter with list comprehension.

Replaced map/filters combo with list comprehension and
exploit Django's ORM features like values_list to generate
all these lists.