Django Query Profiling
Use this skill to turn a vague slow-Django report into a specific queryset, SQL statement, and reproducible scenario.
Workflow
Start from the user-visible slow path.
- Record the URL, API action, background task, management command, or report.
- Capture request parameters, user or tenant shape, pagination state, and data volume.
Collect production or staging evidence.
- Prefer APM transaction traces when available.
- Use database slow-query logs for SQL that is slow independent of Python.
- Use Django Debug Toolbar for server-rendered pages in local development.
- For APIs or jobs, add targeted query logging around the suspicious block.
Map SQL back to Django code.
- Search model table names and column names.
- Inspect view
get_queryset(), serializer fields, template loops, managers, model properties, and signal handlers. - Check whether related-object access happens after the initial queryset was evaluated.
Reproduce locally or in a safe shell.
- Use production-like row counts when possible.
- Disable unrelated instrumentation and debug-only middleware when measuring.
- Keep a repeatable script, test, or shell snippet that exercises the slow path.
Route the fix.
- Query count issue: use
django-orm-query-optimization. - One slow SQL statement: use
django-query-plan-reading. - Large loops or writes: use
django-queryset-batch-processing.
- Query count issue: use
See tooling-and-reproduction.md for concrete profiling snippets and pitfalls.
Good Evidence
- Query count before/after for the specific path.
- The slow SQL or normalized SQL fingerprint.
- Stack or code pointer that explains where the SQL originates.
- Timing from the same environment and representative data shape.
Verification
Do not finish profiling with only a hunch. Finish with a named queryset, code path, and command or request that another agent can re-run.
Source: hashgraph-online/awesome-codex-plugins → plugins/LVTD-LLC/skills/skills/django-query-profiling/SKILL.md