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django-denorm-iplweb is a Django application to provide automatic management of denormalized database fields.

This is a fork of original package, that went by name of django-denorm . This fork should bring original package to the latest Django/Python versions. Also, support for pretty much anything that is not PostgreSQL was dropped.

Supported versions:

  Django 5.2 LTS Django 6.0 Django 6.1
Python 3.10 ✅ ❌ ❌
Python 3.11 ✅ ❌ ❌
Python 3.12 ✅ ✅ ✅
Python 3.13 ✅ ✅ ✅

Licensed under the BSD 3-Clause license.

Requires Celery.

Reasons for this fork being PostgreSQL-only:

  • lack of resources for maintaning other backends,
  • usage of LISTEN/NOTIFY mechanisms, available in PostgreSQL,
  • many more improvements, for example the ability to run multiple instances of cache rebuilder (see docs)

Patches welcome!

Deferring computation

Fields declared with @denormalized are computed synchronously when their model is saved. To skip that for selected fields, e.g. while the Django admin saves a parent object before its inlines, wrap the writes in denorm.deferred(). The fields are then left untouched on UPDATE (or set to their default on INSERT) and marked dirty for flush() on block exit:

import denorm
from django.db import transaction

with transaction.atomic(), denorm.deferred("app.Article.summary"):
    article.save()
    for section in sections:
        section.save()

See the tutorial ("Deferring the computation") for details and limitations.

Dirty instances view

The package ships with an optional view that displays the current number of DirtyInstance rows grouped by content type — useful for monitoring the denormalization queue from a browser instead of running ./manage.py denorm_show_dirtyinstances_count over SSH.

Wire it into your project's URLConf:

# urls.py
from django.urls import include, path

urlpatterns = [
    ...
    path("denorm/", include("denorm.urls")),
]

The view is then reachable at /denorm/dirty-instances/ and via reverse("denorm:dirty_instances_count").

Access policy is controlled by the DENORM_DIRTY_INSTANCES_VIEW_ACCESS setting (default: "staff"):

  • "staff" — only users with is_staff=True (uses staff_member_required).
  • "authenticated" — any logged-in user (uses login_required).
  • "public" — no access control. Only enable this behind your own network-level protection; the page leaks model names from your project.

Example:

# settings.py
DENORM_DIRTY_INSTANCES_VIEW_ACCESS = "authenticated"

Documentation is available from http://django-denorm-iplweb.github.io/django-denorm-iplweb/

Issues can be reported at http://github.com/mpasternak/django-denorm-iplweb/issues