On 23 Nov 2014 22:13, "Christophe Pettus" <x...@thebuild.com> wrote: > > > On Nov 23, 2014, at 1:07 PM, Rick van Hattem <wo...@wol.ph> wrote: > > > > Not really, cause psycopg already fetched everything. > > > > Not if Django limits it by default :) > > Unfortunately, that's not how it works. There are three things that take up memory as the result of a query result: > > 1. The Django objects. These are created in units of 100 at a time. > 2. The psycopg2 Python objects from the result. These are already limited to a certain number (I believe to 100) at a time. > 3. The results from libpq. These are not limited, and there is no way of limiting them without creating a named cursor, which is a significant change to how Django interacts with the database. > > In short, without substantial, application-breaking changes, you can't limit the amount of memory a query returns unless you add a LIMIT clause to it. However, adding a LIMIT clause can often cause performance issues all by itself: > > http://thebuild.com/blog/2014/11/18/when-limit-attacks/ > > There's no clean fix that wouldn't have significant effects on unsuspecting applications.
Very true, that's a fair point. That's why I'm opting for a configurable option. Patching this within Django has saved me in quite a few cases but it can have drawbacks. > -- > -- Christophe Pettus > x...@thebuild.com > > -- > You received this message because you are subscribed to a topic in the Google Groups "Django developers (Contributions to Django itself)" group. > To unsubscribe from this topic, visit https://groups.google.com/d/topic/django-developers/aYwPykvLaMU/unsubscribe. > To unsubscribe from this group and all its topics, send an email to django-developers+unsubscr...@googlegroups.com. > To post to this group, send email to django-developers@googlegroups.com. > Visit this group at http://groups.google.com/group/django-developers. > To view this discussion on the web visit https://groups.google.com/d/msgid/django-developers/CD10DACF-4D0A-458D-BB85-0F7BB8BFF4C0%40thebuild.com . > For more options, visit https://groups.google.com/d/optout. -- 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 receiving emails from it, send an email to django-developers+unsubscr...@googlegroups.com. To post to this group, send email to django-developers@googlegroups.com. Visit this group at http://groups.google.com/group/django-developers. To view this discussion on the web visit https://groups.google.com/d/msgid/django-developers/CAJAwA%3Dx-BC1dy1eXU9Ch2mHYrjk_PSXaj6HewVq%3Dc%2BypXoj37g%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
