Re: Using quicksort for every external sort run

Поиск
Список
Период
Сортировка
От Peter Geoghegan
Тема Re: Using quicksort for every external sort run
Дата
Msg-id CAM3SWZT_oS+-oQy4tMMj9HmSWTHqG7EnUKa0hS41b29Asqa36w@mail.gmail.com
обсуждение исходный текст
Ответ на Re: Using quicksort for every external sort run  (Greg Stark <stark@mit.edu>)
Список pgsql-hackers
On Fri, Dec 11, 2015 at 2:52 PM, Greg Stark <stark@mit.edu> wrote:
> Heh. And if I comment out the presorted check the breakeven point is
> *exactly* where the threshold is today at 7 elements -- presumably
> because Hoare chose it on purpose.

I think it was Sedgewick, but yes. I'd be very hesitant to mess with
the number of elements that we fallback to insertion sort on. I've
heard of people removing that optimization on the theory that it no
longer applies, but I think they were wrong to.

-- 
Peter Geoghegan



В списке pgsql-hackers по дате отправления:

Предыдущее
От: Caleb Welton
Дата:
Сообщение: Re: Bootstrap DATA is a pita
Следующее
От: Caleb Welton
Дата:
Сообщение: Re: Bootstrap DATA is a pita