OK, I've found that if I use .iterator() on the query set, the amount of memory used doesn't grow. So I suppose FileField is somehow (indirectly) referencing something in the retrieved data.
BTW, we've created a fresh Django project with "django-admin startproject" and the problem is present. It looks like a bug in Django. On 13/05/11 10:57, Gustavo Narea wrote: > Hello, > > I've noticed that when you iterate over a query set and use a > FileField instance from each model instance, the memory used by the > process increases every time the loop finishes. This happens on the > Web and command-line interfaces. > > Say you have the following model: > """ > class Bug(Model): > patch = FileField(upload_to="whatever") > """ > > The following loop will make the process use a lot more memory every > time it's run: > """ > for bug in Bug.objects.all()[:1000]: > print "- %s" % bug.patch.name > """ > > But the following loop won't cause memory to grow at all: > """ > for bug in Bug.objects.all()[:1000]: > print "- %s" % bug.__dict__['patch'] > """ > > The mere act of using "bug.patch" causes the problem, regardless of > what member of "patch" you use (e.g., "name", "url"). The same happens > with ImageField and presumably any other subclass of FileField. > > According to the "strace" utility, the process doesn't even try to > access the file in any way. In fact, if I remove the files from the > file system, the problem is still present. I've also checked the > Postgres statement logs and the only query issued looks absolutely > fine. > > I'm using Python 2.5, Django 1.1.4 and Ubuntu (it also happens on > Debian boxes). I got DEBUG set to False. > > I'll continue to look at this to see what's exactly going on here, but > I'm posting here to see if someone could shed some lights. I'll post > my findings. > > Cheers. > > - Gustavo Narea. -- Gustavo Narea. Software Developer. 2degrees, Ltd. <http://dev.2degreesnetwork.com/>. -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
