It's done more like explaining a side-effect than explaining the *purpose* of the method. It shouldn't be "notice that when you use `exists`, it has the following effects on efficiency", but "`exists`'s entire purpose is to get higher efficiency in situations where you don't want to access the data."
On Fri, Jan 18, 2013 at 6:08 PM, Javier Guerra Giraldez <jav...@guerrag.com>wrote: > On Fri, Jan 18, 2013 at 10:58 AM, Ram Rachum <r...@rachum.com> wrote: > > I suggest copying your explanation into the documentation. > > it's already there: > > " This means that calling QuerySet.exists() is faster than > bool(some_query_set), but not by a large degree. If some_query_set has > not yet been evaluated, but you know that it will be at some point, > then using some_query_set.exists() will do more overall work (one > query for the existence check plus an extra one to later retrieve the > results) than simply using bool(some_query_set), which retrieves the > results and then checks if any were returned." > > [ > https://docs.djangoproject.com/en/1.4/ref/models/querysets/#django.db.models.query.QuerySet.exists > ] > > > -- > Javier > > -- > You received this message because you are subscribed to the Google Groups > "Django developers" group. > To post to this group, send email to django-developers@googlegroups.com. > To unsubscribe from this group, send email to > django-developers+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/django-developers?hl=en. > > -- You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@googlegroups.com. To unsubscribe from this group, send email to django-developers+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-developers?hl=en.
