Hi Ram, On 01/18/2013 06:25 AM, Ram Rachum wrote: > Can someone who's familiar with Django internals please confirm or deny > the following answer to my question? > > http://stackoverflow.com/a/14369747/76701
That answer is correct. A common situation for evaluating a queryset in a boolean context is that you're about to use the results if there are any, in which case it's more efficient to fetch all the data right away rather than doing a COUNT query and then a second query to fetch all the data. The only time "exists()" is more efficient is when _all_ you want is to know whether there are any matching rows; you're not going to do anything with the rows themselves. When the existence-check is just a path on the way to the "real" use of the queryset, you can be quick and implicit; when the existence check is all that you care about, you say so explicitly by using "exists()". Carl -- 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.
