Re: WIP: patch to create explicit support for semi and anti joins

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: WIP: patch to create explicit support for semi and anti joins
Дата
Msg-id 21651.1218733706@sss.pgh.pa.us
обсуждение исходный текст
Ответ на Re: WIP: patch to create explicit support for semi and anti joins  (Simon Riggs <simon@2ndquadrant.com>)
Список pgsql-hackers
Дерево обсуждения 
Simon Riggs <simon@2ndquadrant.com> writes:
> OK, that sounds good. Are you also working on transforming NOT IN into
> different form? Or is that the same thing as (1)?

I'm not currently thinking about NOT IN.  It could be transformed to
an antijoin if we could prove that no nulls are involved, but that
seems less than trivial as I noted earlier.
        regards, tom lane

В списке pgsql-hackers по дате отправления:

Предыдущее
От: Simon Riggs
Дата:
Сообщение: Re: WIP: patch to create explicit support for semi and anti joins
Следующее
От: Simon Riggs
Дата:
Сообщение: Re: IN vs EXISTS equivalence