Wow, this is an excellent discussion - and I must admit, a bit beyond
my abilities. Is there a consensus as to the best approach to adopt?
Is Elliot's the best?
On 10/22/13, Rémi Cura <remi.cura@gmail.com> wrote:
> OK,
> just out of pure curiosity,
> is it always the case or is it due to this particular aggregate?
>
> Cheers,
> Rémi-C
>
>
> 2013/10/22 Merlin Moncure <mmoncure@gmail.com>
>
>> On Tue, Oct 22, 2013 at 9:43 AM, Rémi Cura <remi.cura@gmail.com> wrote:
>> > Thanks again for the precision !
>> >
>> > I still don't understand perfectly. We call the aggregate n times, and
>> each
>> > time we compute the aggregate, using (potentially) n rows, thus
>> > becoming
>> (at
>> > most) O(n*n).
>> >
>> > With a standard loop, I loop n times, and each times I only need the
>> current
>> > row plus the previous row which I put in memory, thus O(n).
>>
>> For posterity, the above is incorrect. Since the aggregate is ordered
>> through the window function, it gets executed exactly once per output
>> row. It behaves exactly like a loop. You know this because there is
>> no array in the aggregate state.
>>
>> merlin
>>
>