id summary reporter owner description type status component version severity resolution keywords cc stage has_patch needs_docs needs_tests needs_better_patch easy ui_ux 28933 Optimize the queries for ModelAdmin.date_hierarchy hakib nobody "The predicate generated by `ModelAdmin.date_hierarchy` makes it very difficult for databases to optimize the query. The following date hierarchy: `/admin/app/model?created__year=2017&created__month=12&created__day=16` generates the following WHERE clause (PostgreSQL): `WHERE created between '2017-01-01' and '2017-31-12' and EXTRACT('month', created) = 12 and EXTRACT('day', created) = 16` The query above will not be able to utilize range based indexes on the date hierarchy column - on big tables this has a significant performance impact. The current implementation of date hierarchy is relying on the ""default"" filtering mechanism used by the admin. I propose implementing custom filtering for that will better utilize it's hierarchical nature and make it more database friendly. Instead of the query above the date hierarchy would generate the following predicates for different levels of the hierarchy: {{{ /admin/app/model?created__year=2017&created__month=12&created__day=16 WHERE created >= '2017-12-16' and created < '2017-12-17' }}} {{{ /admin/app/model?created__year=2017&created__month=12 WHERE created >= '2017-12-01' and created < '2018-01-01' }}} {{{ /admin/app/model?created__year=2017 WHERE created >= '2017-01-01' and created < '2018-01-01' }}} I already [https://codeburst.io/django-admin-range-based-date-hierarchy-37955b12ea4e wrote about this issue] and [https://github.com/hakib/django-admin-lightweight-date-hierarchy/blob/master/django_admin_lightweight_date_hierarchy/admin.py published a package] that implements the above as a custom `SimpleListFilter`. I already have a PR ready - I'm following proper protocol here so please let me know if this is acceptable." Cleanup/optimization closed contrib.admin 2.0 Normal fixed date_hierarchy Accepted 1 0 0 1 0 0