Duplicate query in archive and year class based views
|Reported by:||aaugustin||Owned by:||nobody|
|Has patch:||no||Needs documentation:||no|
|Needs tests:||no||Patch needs improvement:||no|
In BaseArchiveIndexView and BaseYearArchiveView, get_dated_items:
- calls get_dated_queryset, which is going trigger the evaluation of said queryset (unless pagination is enabled);
- adds a new ordering clause on the queryset before making it the object_list.
Because of the added ordering clause, the queryset will be re-evaluated when accessing context['object_list'] / context[context_object_name].
The ordering clause should probably be moved into get_dated_queryset. There are two ways to achieve this:
- Add an optional ordering parameter to get_dated_queryset. This is the fastest solution and it'll be totally backwards compatible.
- Add an API to control the order of the queryset for all views. Currently no order is enforced, unless the model's meta.ordering is set -- which is often a bad practice as it adds the sorting overhead to every query involving the models.
I'm probably going to adopt the first solution to fix this problem. The second is a larger feature request.