Why is a query being slow in Django?

Question

Django

There is a request like this:

pcollections = PCollection.objects.filter(
    product__category__title__in = filter_items_active['categories_get'] ,
    product__color__title__in = filter_items_active['colors_get'] ,
    product__surface__title__in = filter_items_active['surfaces_get'] ,
    product__width_height__title__in = filter_items_active['width_heights_get'] ,
    product__price_type__title__in = filter_items_active['pricetypes_get'] ,
    fabrika__title__in = filter_items_active['fabriks_get'] ,
    product__appointment__title__in = filter_items_active['appointments_get'] ,
    product__premises__title__in = filter_items_active['premises_get'] ,
    fabrika__country__title__in = filter_items_active['countrys_get'] ,
    product__picture__title__in = filter_items_active['pictures_get'] ,
    product__form__title__in = filter_items_active['forms_get'] ,
    product__rectificate__in = filter_items_active['rectificate_get'] ,
    product__stock__in = filter_items_active['stock_get']
  ).distinct()

Runs very slowly. Can you tell me how to optimize it?

Answer 1

sportik174 Well, here it's worth starting with the fact that you are searching for a string, I guess that there are no indexes on the title.
In short, you shouldn't do this.

product__category__title__in = filter_items_active['categories_get']

and you should do it like this

product__category_id__in = filter_items_active['categories_get']

where in categories_get you pass not strings, but category ids, and so on with all other parameters

Answer 2

Start by analyzing the query execution plan in SQL
Shl, although there is complete trash here, you need to filter not by title, by id of the corresponding tables. For rectificate and stock you could do this.