strawberry-graphql/strawberry-django

N+1 queries due to queryset.count() if cache is empty

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#788 opened on Sep 30, 2025

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enhancementhelp wanted

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Description

Describe the Bug

In a nested ListConnectionWithTotalCount, if the child has total_count in the query, if there is a parent node with no related child nodes, there is a queryset.count() triggered. This leads to N+1 queries like scenario if very few parent nodes have child nodes.

https://github.com/strawberry-graphql/strawberry-django/blob/269954c582dfa38dc93af95abd2a275888f50103/strawberry_django/pagination.py#L269-L298

Instead, if the queryset is optimized (is_optimized_by_prefetching is True) and there is no offset / limit mentioned then it should just return 0 assuming no nodes were found, calling the count() method only for unoptimized querysets.

Contributor guide

Research direction
Investigate the condition where `is optimized by prefetching` is True and no offset/limit to avoid unnecessary count() queries.
Tech stack
python
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
PythonDjangoGraphQL
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60