Re: PL/pgSQL support to define multi variables once

On Fri, Jun 13, 2014 at 11:32 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> David G Johnston <david(dot)g(dot)johnston(at)gmail(dot)com> writes:
> > Tom Lane-2 wrote
> >> At the very least I think we should stay away from this syntax until
> >> the SQL committee understand it better than they evidently do today.
> >> I don't want to implement it and then get caught by a future
> >> clarification that resolves the issue differently than we did.
>
> > Its not quite as unclear as you make it out to be:
>
> Yes it is.
>
>
​Not withstanding the decision making of the SQL committee I was rejecting
as inconsistent:

SET random_1 = 0;
SET random_2 = 0;
SET random_3 = random(1234); ​

The ambiguity regarding re-execute or copy still remains.

> That's not the reading I want, and it's not the reading you want either,
> but there is nothing in the existing text that justifies single
> evaluation. So I think we'd be well advised to sit on our hands until
> the committee clarifies that. It's not like there is some urgent reason
> to have this feature.
>
>
>
Agreed.

I don't suppose there is any support or prohibition on the :

one,two,three integer := generate_series(1,3)​;

interpretation...not that I can actually come up with a good use case that
wouldn't be better implemented via a loop in the main body.

David J.