Re: [HACKERS] TABLE-function patch vs plpgsql

2008/7/29 Hannu Krosing <hannu@krosing.net>:
> On Thu, 2008-07-17 at 19:13 -0400, Tom Lane wrote:
>> I've been working on the TABLE-function patch, and I am coming to the
>> conclusion that it's really a bad idea for plpgsql to not associate
>> variables with output columns --- that is, I think we should make
>> RETURNS TABLE columns semantically just the same as OUT parameters.
>
> I just looked at recent cahnges in pl/python, and found out that RETURNS
> TABLE is _NOT_ semantically just the same as OUT parameters, at least at
> API level.
>
> Why can't it be ?
>
> Why is PROARGMODE_TABLE needed at all ?

because I need to separate classic OUT args from table args. TABLE
function has more clean syntax, then our SRF functions, and it isn't
related only to SQL/PSM. It works nice together with SQL language.
Actually TABLE variables are exactly same as OUT variables (in
plpgsq), that is possible, but I am not sure, if it's best too.

I have prototype where is possible declare variables derivated from
function return type
create function foo(..) returns table(x int, y int) as $$
declare result foo%rowtype; resx foo.x%type; ....

all this has to minimalist risk of variables and sql object name collisions.

Regards
Pavel Stehule

>
>> 4. It's a whole lot easier to explain things if we can just say that
>> OUT parameters and TABLE parameters work alike. This is especially
>> true when they actually *are* alike for all the other available PLs.
>
> It would be nice, if they were the same at API level as well.
>
> --------------------
> Hannu
>
>

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