Re: Incorrect explain output for updates/delete operations with returning-list on partitioned tables

On Tue, 7 May 2024 at 09:18, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> SAIKIRAN AVULA <avulasaikiranreddy(at)gmail(dot)com> writes:
> > I have been working on partitioned tables recently, and I have noticed
> > something that doesn't seem correct with the EXPLAIN output of an
> > update/delete query with a returning list.
>
> What do you think is not right exactly? The output has to use some
> one of the correlation names for the partitioned table. I think
> it generally chooses the one corresponding to the first Append arm,
> but really any would be good enough for EXPLAIN's purposes.

Also looks harmless to me. But just a slight correction, you're
talking about the deparse Append condition that's in
set_deparse_plan(). Whereas the code that controls this for the
returningList is the following in nodeModifyTable.c:

/*
* Initialize result tuple slot and assign its rowtype using the first
* RETURNING list. We assume the rest will look the same.
*/
mtstate->ps.plan->targetlist = (List *) linitial(node->returningLists);

David