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

On 2016-09-12 10:19:14 -0400, Tom Lane wrote:
> Andres Freund <andres(at)anarazel(dot)de> writes:
>
> > 0001-Add-some-more-targetlist-srf-tests.patch
> > Add some test.
>
> I think you should go ahead and push this tests-adding patch now, as it
> adds documentation of the current behavior that is a good thing to have
> independently of what the rest of the patchset does. Also, I'm worried
> that some of the GROUP BY tests might have machine-dependent results
> (if they are implemented by hashing) so it would be good to get in a few
> buildfarm cycles and let that settle out before we start changing the
> answers.

Generally a sound plan - I started to noticeably expand it though,
there's some important edge cases it didn't cover.

> Although tsrf.sql doesn't currently need to create any views, it doesn't
> seem like a great idea to assume that it never will. Maybe add this
> after misc_functions in the previous parallel group, instead?

WFM

> +-- it's weird to GROUP BYs that increase the number of results
>
> "it's weird to have ..."
>
> +-- nonsensically that seems to be allowed
> +UPDATE fewmore SET data = generate_series(4,9);
>
> "nonsense that seems to be allowed..."
>
> +-- SRFs are now allowed in RETURNING
> +INSERT INTO fewmore VALUES(1) RETURNING generate_series(1,3);
>
> s/now/not/, apparently

Err, yes. Will update.

Greetings,

Andres Freund