Re: Implement targetlist SRFs using ROWS FROM() (was Changed SRF in targetlist handling)

On 2016-09-12 13:26:20 -0400, Tom Lane wrote:
> Andres Freund <andres@anarazel.de> writes:
> > On 2016-09-12 12:10:01 -0400, Tom Lane wrote:
> >> I can't say that I like the proposed syntax much.
> 
> > Me neither. But I haven't really found a better approach.  It seems
> > kinda consistent to have ROWS FROM (... AS ()) change the picked out
> > columns to 0, and just return the whole thing.
> 
> I just remembered that we allow zero-column composite types, which
> makes this proposal formally ambiguous.  So we really need a different
> syntax.  I'm not especially in love with the cast-to-record idea, but
> it does dodge that problem.

I kind of like ROWS FROM (... AS VALUE), that seems to confer the
meaning quite well. As VALUE isn't a reserved keyword, that'd afaik only
really work inside ROWS FROM() where AS is required.