Re: [Django] #32089: prefetch_related_objects() does not set the to_attr on all instances if the first instance in the list already has it.

[Django]

#32089: prefetch_related_objects() does not set the to_attr on all instances if the
first instance in the list already has it.
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Reporter: Dennis Kliban | Owner: nobody
Type: Bug | Status: closed
Component: Database layer | Version: 2.2
(models, ORM) |
Severity: Normal | Resolution: needsinfo
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
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Comment (by François Freitag):

> Our project processes instances in a stream.

Could you give more details on that? `prefetch_related_objects()` loads
all objects upfront due to
https://github.com/django/django/blob/stable/2.2.x/django/db/models/query.py#L1546.
Even with an overloaded `__bool__`, the `QuerySet` is iterated over by
https://github.com/django/django/blob/stable/2.2.x/django/db/models/query.py#L1585.

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Ticket URL: <https://code.djangoproject.com/ticket/32089#comment:3>
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