Re: FETCH FIRST clause PERCENT option

Поиск
Список
Период
Сортировка
От Surafel Temesgen
Тема Re: FETCH FIRST clause PERCENT option
Дата
Msg-id CALAY4q-0Ofi497ng49f27se5mMa0rb+9f1F8155QVWUOFccv-Q@mail.gmail.com
обсуждение исходный текст
Ответ на Re: FETCH FIRST clause PERCENT option  (Tomas Vondra <tomas.vondra@2ndquadrant.com>)
Ответы Re: FETCH FIRST clause PERCENT option  (Tomas Vondra <tomas.vondra@2ndquadrant.com>)
Список pgsql-hackers
Дерево обсуждения


On Sun, Feb 10, 2019 at 2:22 AM Tomas Vondra <tomas.vondra@2ndquadrant.com> wrote:
 

I'm not sure I understand - are you saying every time the user does a
FETCH, we have to run the outer plan from scratch? I don't see why would
that be necessary? And if it is, how come there's no noticeable
performance difference?

Can you share a patch implementing the incremental approach, and a query
demonstrating the issue?


I didn't implement it but its obvious that it doesn't work similarly with previous approach.

We need different implementation and my plan was to use tuplestore per call and clear

it after returning tuple but I see that the plan will not go far because mainly the last returned

slot is not the last slot we get from outerPlan execution


regards

Surafel 

В списке pgsql-hackers по дате отправления:

Предыдущее
От: Pavel Stehule
Дата:
Сообщение: Re: proposal: variadic argument support for least, greatest function
Следующее
От: John Naylor
Дата:
Сообщение: Re: WIP: Avoid creation of the free space map for small tables