Re: Problem using set-returning functions - Mailing list pgsql-sql

On Mon, 27 Mar 2006, Markus Schaber wrote:

> Hi, John,
>
> John DeSoi wrote:
>
> > With SRFs, you need to specify what you want to select. In other  words
> > if you are calling generate_x(bar) you need "select * from
> > generate_x(bar)" -- "select generate_x(bar)" will not work.
>
> So, then, why does it work with generate_series() and dump()?

It's an implementation detail. Some languages handle SRFs in a way that
can be handled in the select list (SQL and C I think) and others do not
(plpgsql). The latter will likely change at some point, although there are
some confusing issues with SRFs in the select list as well, see the
difference in behavior between:

select generate_series(1,10), generate_series(1,5);vs
select * from generate_series(1,10) g1, generate_series(1,5) g2;