Re: Insert Documentation - Returning Clause and Order

On Thursday, December 10, 2020, Ashutosh Bapat <ashutosh(dot)bapat(dot)oss(at)gmail(dot)com>
wrote:

> On Wed, Dec 9, 2020 at 9:10 PM David G. Johnston
> <david(dot)g(dot)johnston(at)gmail(dot)com> wrote:
> >
> > Hey,
> >
> > Would it be accurate to add the following sentence to the INSERT
> documentation under "Outputs"?
> >
> > "...inserted or updated by the command." For a multiple-values
> insertion, the order of output rows will match the order that rows are
> presented in the values or query clause.
>
> Postgres's current implementation may be doing so, but I don't think
> that can be guaranteed in possible implementations. I don't think
> restricting choice of implementation to guarantee that is a good idea
> either.
>
>
Yeah, the ongoing work on parallel inserts would seem to be an issue. We
should probably document that though. And maybe as part of parallel
inserts patch provide a user-specifiable way to ask for such a guarantee if
needed. ‘Insert returning ordered”

David J.