Re: Function execution costs 'n all that

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: Function execution costs 'n all that
Дата
Msg-id 4748.1169064806@sss.pgh.pa.us
обсуждение исходный текст
Ответ на Re: Function execution costs 'n all that  (Ron Mayer <rm_pg@cheapcomplexdevices.com>)
Список pgsql-hackers
Ron Mayer <rm_pg@cheapcomplexdevices.com> writes:
> Tom Lane wrote:
>> BTW, I'm thinking that a "cost constant" probably ought to be measured
>> in units of cpu_operator_cost.

> Any chance that costs could eventually change to real-world units?

Define "real world units".

If you like you can try to adjust things so that cpu_operator_cost bears
some relation to elapsed-msec-on-your-own-machine, and scale everything
else accordingly; indeed that's why we added seq_page_cost in 8.2.
But it's awfully hard to see the numbers being very portable.
        regards, tom lane


В списке pgsql-hackers по дате отправления:

Предыдущее
От: Ron Mayer
Дата:
Сообщение: Re: Function execution costs 'n all that
Следующее
От: Tom Lane
Дата:
Сообщение: Design notes for EquivalenceClasses