Re: Solving the select+1 problem.

[Stratos Moros]

Given their sample code, my initial impression was that it was indeed 
automatic. Looking a bit closer, there seems to be hardcoded logic 
inside the DataSource (the thing I'm assuming provides getAllUserIds and 
getUsernameById) to specifically fetch all ids and then all names for 
those ids. So they're still doing a manual prefetch_related equivalent 
but at a different abstraction level.


I should note that my Haskell knowledge is also minimal, so it is quite 
possible that I'm misunderstanding something.



On 11 Jun 2014, at 17:36, Alex Gaynor wrote:

I also do not really know Haskell (I'm sensing a trend...), that said, 
it
seems to me the cool part of haxl is that it can be automatic -- 
analagous

to if writing {{ post.author.name }} in a template caused
select_related("author") to automatically be applied to the queryset 
that

yielded post.

Alex


On Wed, Jun 11, 2014 at 6:37 AM, Jacob Kaplan-Moss 


wrote:

I'm not great at Haskell, either, but this looks to me to be very 
similar

to prefetch_related (
https://docs.djangoproject.com/en/dev/ref/models/querysets/#prefetch-related
).

Jacob


On Wed, Jun 11, 2014 at 6:15 AM, Jonathan Slenders <
jonathan.slend...@gmail.com> wrote:

The "select+1" problem is a problem that people often face in 
Django.

Usually, something like select_related solves it, but I don't think
that's always possible.

Facebook released Haxl today and there's an example of their apprach 
to

the problem.
https://github.com/facebook/Haxl/tree/master/example/sql

I don't know enough Haskel to understand this code, but it could 
contain

some very nice ideas that apply to our ORM as well.

Cheers,
Jonathan

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Re: Solving the select+1 problem.

[Alex Gaynor]

I also do not really know Haskell (I'm sensing a trend...), that said, it
seems to me the cool part of haxl is that it can be automatic -- analagous
to if writing {{ post.author.name }} in a template caused
select_related("author") to automatically be applied to the queryset that
yielded post.

Alex


On Wed, Jun 11, 2014 at 6:37 AM, Jacob Kaplan-Moss 
wrote:

> I'm not great at Haskell, either, but this looks to me to be very similar
> to prefetch_related (
> https://docs.djangoproject.com/en/dev/ref/models/querysets/#prefetch-related
> ).
>
> Jacob
>
>
> On Wed, Jun 11, 2014 at 6:15 AM, Jonathan Slenders <
> jonathan.slend...@gmail.com> wrote:
>
>> The "select+1" problem is a problem that people often face in Django.
>> Usually, something like select_related solves it, but I don't think
>> that's always possible.
>>
>> Facebook released Haxl today and there's an example of their apprach to
>> the problem.
>> https://github.com/facebook/Haxl/tree/master/example/sql
>>
>> I don't know enough Haskel to understand this code, but it could contain
>> some very nice ideas that apply to our ORM as well.
>>
>> Cheers,
>> Jonathan
>>
>> --
>> You received this message because you are subscribed to the Google Groups
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>> 
>> .
>> For more options, visit https://groups.google.com/d/optout.
>>
>
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Re: Solving the select+1 problem.

[Jacob Kaplan-Moss]

I'm not great at Haskell, either, but this looks to me to be very similar
to prefetch_related (
https://docs.djangoproject.com/en/dev/ref/models/querysets/#prefetch-related
).

Jacob


On Wed, Jun 11, 2014 at 6:15 AM, Jonathan Slenders <
jonathan.slend...@gmail.com> wrote:

> The "select+1" problem is a problem that people often face in Django.
> Usually, something like select_related solves it, but I don't think that's
> always possible.
>
> Facebook released Haxl today and there's an example of their apprach to
> the problem.
> https://github.com/facebook/Haxl/tree/master/example/sql
>
> I don't know enough Haskel to understand this code, but it could contain
> some very nice ideas that apply to our ORM as well.
>
> Cheers,
> Jonathan
>
> --
> You received this message because you are subscribed to the Google Groups
> "Django developers" group.
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> email to django-developers+unsubscr...@googlegroups.com.
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> To view this discussion on the web visit
> https://groups.google.com/d/msgid/django-developers/f81a5db1-9777-4cd0-98b7-25b0bc44f498%40googlegroups.com
> 
> .
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>

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Solving the select+1 problem.

[Jonathan Slenders]

The "select+1" problem is a problem that people often face in Django.
Usually, something like select_related solves it, but I don't think that's 
always possible.

Facebook released Haxl today and there's an example of their apprach to the 
problem.
https://github.com/facebook/Haxl/tree/master/example/sql

I don't know enough Haskel to understand this code, but it could contain 
some very nice ideas that apply to our ORM as well.

Cheers,
Jonathan

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