Opened 5 years ago

Last modified 16 months ago

#29984 closed New feature

Support prefetch_related() with Queryset.iterator() — at Version 4

Reported by: Taylor H Owned by: nobody
Component: Database layer (models, ORM) Version: dev
Severity: Normal Keywords:
Cc: Triage Stage: Ready for checkin
Has patch: yes Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: no UI/UX: no

Description (last modified by Asif Saifuddin Auvi)

I was surprised when I found out that prefetch_related calls are ignored when using Queryset.iterator. I noticed in the docs here ​https://docs.djangoproject.com/en/dev/ref/models/querysets/#iterator that it is because the "these two optimizations do not make sense together." That may have been true in the past, but it is definitely not the case now. The iterator allows chunking (by default 2000) and it would be very helpful to prefetch related for each chunk.

Change History (4)

comment:1 by Tim Graham, 5 years ago

Summary: Support prefetch_related with Queryset.iterator → Support prefetch_related() with Queryset.iterator()
Triage Stage: Unreviewed → Accepted

The situation isn't completely straightforward. There's a discussion on ​django-developers. Accepting the ticket to do something.

comment:2 by Raphael Kimmig, 5 years ago

I've created a proof of concept implementation ​https://github.com/django/django/pull/10707/

I think prefetching is probably closer to what a user would expect from the api.

comment:3 by David Foster, 5 years ago

Has patch: set
Needs documentation: set

comment:4 by Asif Saifuddin Auvi, 4 years ago

Description: modified (diff)
Version: 2.1 → master
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