Tuesday, April 28, 2015

Re: Context manager to pick which database to use?

Thanks for the reply Simon. Yeah, I'm using `using` for now, just thought it'd be nice to somehow wrap the logic, especially if it could magically pass through to underlying function calls. I am experimenting with having a `readonly` manager that just adds a `.using('readonly')`, dunno how ~djangonic~ that is.


On Tuesday, April 28, 2015 at 3:58:15 PM UTC-4, Simon Charette wrote:
Hi Peter,

I think you could use database routers to declare the default behavior and rely on the using() queryset method for the exceptional case?

I'm afraid the introduction of a context manager would require the addition of a thread-local global state that a database router could rely on.


Le mardi 28 avril 2015 15:26:48 UTC-4, Peter Coles a écrit :
When using multiple databases, I would love for a simple way to declare which database should be used during execution of django ORM calls. Perhaps this could even use a context manager and look something like this:

# declare that all calls within this context should default to using 'readonly' db instead of 'default'
with database('readonly'):
= models.MyThing.objects.all()

# inside this function call the 'readonly' db would be used too (unless overridden by `.using(...)`)
= some_lib.some_function(things)

In my app I have a write database and a read-only replica. The read-only replica might have a delay, so I don't want to use it in normal live requests, but I would like certain dashboards to use it. For this reason I assume that the database router approach doesn't properly apply?

Does something like this exist? If not, any thoughts on if it might be useful and where I might consider poking around in the ORM?

You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users+unsubscribe@googlegroups.com.
To post to this group, send email to django-users@googlegroups.com.
Visit this group at http://groups.google.com/group/django-users.
To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/fdcec8f6-4b00-43c0-8584-77ba68c9d61c%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

No comments:

Post a Comment