Django QuerySet Batch Processing

Use this skill when Django code processes many rows. The goal is to avoid loading unnecessary model instances, avoid queryset result-cache blowups, and move writes into set-based database operations when behavior allows.

Workflow

1. Identify the per-row work.

   • Is it read-only export/reporting?
   • Does it need model methods, validation, or signals?
   • Can the database compute or update the value directly?

2. Choose the read pattern.

   • Use values() or values_list() for scalar exports and reports.
   • Use iterator(chunk_size=...) when model instances are needed but queryset caching is not.
   • Keep ordering deliberate; unnecessary ordering costs work.