Prefetch with optimize and only optimization enabled causes N+1

[rcybulski1122012]

Describe the Bug

As the title says - if have the only optimization enabled and I optimize a queryset that is prefetched, it is going to cause N+1, problem because the id field that is used to matched the prefetch objects is excluded from the queryset.

Not sure if it's a bug or expected behaviour but I spend some time debugging it 😅. I solved the problem by disabling the only optimization, by passing the config instance to the optimize.

If it's not a bug I'd appreciate a more specific documentation on optimizer 🙏

prefetched_fields: list[SomeFieldType] = strawberry_django.field(
    prefetch_related=lambda info: Prefetch(
      "some_fields",
      queryset=optimize(SomeField.objects.filter(...)),
      to_attr="prefetched_fields"
    )
)

System Information

• Operating system: MacOs 14.8 (23J21)
• Python version: 3.12

[rcybulski1122012]

My bad, not this repo 😅