Re: WIP patch: convert SQL-language functions to return tuplestores

Поиск
Список
Период
Сортировка
От Robert Haas
Тема Re: WIP patch: convert SQL-language functions to return tuplestores
Дата
Msg-id 603c8f070810301011y2a8dfac8m94195eaae7909a76@mail.gmail.com
обсуждение исходный текст
Ответ на Re: WIP patch: convert SQL-language functions to return tuplestores  ("Pavel Stehule" <pavel.stehule@gmail.com>)
Ответы Re: WIP patch: convert SQL-language functions to return tuplestores  ("Pavel Stehule" <pavel.stehule@gmail.com>)
Список pgsql-hackers
> With session variables we could implement srf function in plpgsql like
> current C srf function. Like
>
> create or replace function foo(....)
> returns record as $$
> #option with_srf_context(datatype of srf context)
> begin
>   return row(...);
> end;
> $$ language plpgsql;

Oh, sure - but what you can do with this will be somewhat limited
compared to a Perl hash reference off which you can chain any
arbitrary data structure with ease.  I'd want to see an actual use
case for this before anyone bothered implementing it.  I was actually
thinking one way to do it would be to extend the variable declaration
syntax so that you could declare n>=0 variables as SRF context
variables, which I think is nicer, but even that I think is of limited
usefulness.  I think the biggest value of PL/plgsql is the ability to
RETURN QUERY, and I think the ability to push a lazy execution model
down into that subordinate query is where the win is.  That case won't
be helped at all by this sort of alternate calling convention - in
fact it'll be nearly impossible to even do that at all with this type
of execution model.

...Robert


В списке pgsql-hackers по дате отправления:

Предыдущее
От: Zdenek Kotala
Дата:
Сообщение: [PATCH] HeapTuple version extension + code cleanup
Следующее
От: "Jonah H. Harris"
Дата:
Сообщение: Re: Block-level CRC checks