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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/571d5cb6-bd53-4db4-aad1-2a820d71782en%40googlegroups.com.
