Complexity nomenclature

[ZombineDev via Digitalmars-d]

On Friday, 4 December 2015 at 09:17:07 UTC, Ola Fosheim Grøstad 
wrote:
> On Friday, 4 December 2015 at 09:09:35 UTC, ZombineDev wrote:
>> and space complexity (the correctness is given). Otherwise, 
>> designing large systems becomes impossible, because all large 
>> systems have hard performance requirements.
>
> I am sorry to say this, but hard performance requirements 
> require O(1) on everything.
>
> Big-Oh tells you essentially very little if it is more than 
> O(1). Quick sort and insertion sort are O(N^2), bucket sort is 
> O(N). That does not make bucket sort faster than quick sort or 
> even insertion sort on a specific case as it is dominated by 
> the number of possible values.

Well, I agree, but I didn't say hard real-time, only performance 
requirements that are hard to achieve because the system is 
large, and becuase it would cost even more if the system was 
larger (slower).