Re: Automatic prefetching in querysets

My existing code for this is now available as a pypi package https://github.com/tolomea/django-auto-prefetch -- You received this message because you are subscribed to the Google Groups "Django developers (Contributions to Django itself)" group. To unsubscribe from this group and stop receivin

Re: Sealing or locking QuerySets -- a suggestion to prevent surprise N+1 queries.

Regarding auto prefetch, after the discussion here I created a ticket https://code.djangoproject.com/ticket/28586 It didn't get much attention presumably because it was around Django 2 release time. I have a todo note to add tests and doco and generally get it to a mergable state in order to pus

Re: Automatic prefetching in querysets

This received some positive responses, so to help move the conversation along I have created a ticket and pull request. https://code.djangoproject.com/ticket/28586 https://github.com/django/django/pull/9064 Regards G On Tue, Aug 15, 2017 at 10:44 AM, Gordon Wrigley wrote: > I'd

Re: Automatic prefetching in querysets

I'm not advocating either way on this, but it's probably worth noting that the context manager proposal is compatible with a queryset level optin/out and an object level optout. So you could for example have prefetch_related(auto=None) which can be explicitly set to True / False and takes it's val

Re: Automatic prefetching in querysets

Regarding 2, it does work for reverse one-to-one relations. On Wed, Aug 16, 2017 at 9:17 PM, Aymeric Augustin < aymeric.augus...@polytechnique.org> wrote: > On 15 Aug 2017, at 11:44, Gordon Wrigley wrote: > > I'd like to discuss automatic prefetching in querysets. Specific

Re: Automatic prefetching in querysets

ons like these you simply cannot know in >>>> advance whether doing extra queries is going to a be an optimization or a >>>> pessimization. If I can come up with a single example where it would >>>> significantly decrease performance (either memory usage or speed

Re: Automatic prefetching in querysets

ion would be for Django to detect these O(n) query > cases and display intelligent warnings, with suggestions as to the correct > select/prefetch calls to add. When debug mode is enabled we could detect > repeated foreign key referencing from the same source. > > On 15 Aug 2017 19:44, &qu

Re: Automatic prefetching in querysets

tions? I don't, but unlike Django where I have years of experience I have next to no experience with other ORM's. Regards G On Tue, Aug 15, 2017 at 7:44 PM, Gordon Wrigley wrote: > Sorry maybe I wasn't clear enough about the proposed mechanism. > > Currentl

Re: Automatic prefetching in querysets

, Aug 15, 2017 at 8:03 PM, Collin Anderson wrote: > Hi Gordon, > > How is it implemented? Does each object keep a reference to the queryset > it came from? > > Collin > > On Tue, Aug 15, 2017 at 2:44 PM, Gordon Wrigley > wrote: > >> Sorry maybe I wasn&#x

Re: Automatic prefetching in querysets

u know of any other ORMs which attempt similar magical optimisations? > How do they go about identifying the cases where it is necessary? > > On 15 August 2017 at 10:44, Gordon Wrigley > wrote: > >> I'd like to discuss automatic prefetching in querysets. Specifically >

Automatic prefetching in querysets

I'd like to discuss automatic prefetching in querysets. Specifically automatically doing prefetch_related where needed without the user having to request it. For context consider these three snippets using the Question & Choice models from the tutorial