Dear django users, when working on very large datasets (millions of items) and performing queries on it, I have a few questions regaring the performance.
- From my understanding using `bool(qs)` is preferred over using `qs.exists()` when the queryset is used later on, as `bool(qs)` already evaluates and caches the qs, which `qs.exists()` does not. Is that correct? - Is the above assumption also true, when the qs that has bee evaluated by using `bool(qs)` afterwards is accessed by e.g. `qs.earliest(some_property)`,? Or does `qs.earliest(some_property)` generate a new qs and hence there is not really an advantage of having the original qs already evaluated by `bool(qs)`? E.g. using `.filter()` will surely create and return a new qs, as stated in the docu and in this case I am pretty sure, the advantage of evaluating and caching the qs by using `bool(qs)` is lost here. But for `earliest()` or `latest()` the docu only states, that an object is returned. It does not say anything about a new queryset being created. Hence my questions.. Thanks a lot and happy coding Juergen -- 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+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/571d5cb6-bd53-4db4-aad1-2a820d71782en%40googlegroups.com.
