Re: pg_plan_advice

Thanks for the review!

On Mon, Feb 2, 2026 at 2:37 PM Alexandra Wang
<alexandra(dot)wang(dot)oss(at)gmail(dot)com> wrote:
> 0001:
> The code looks good to me. However, I feel a bit uneasy about not
> seeing a test case for the additional subplan origin display added in
> pg_overexplain. Maybe we could add the following test cases to
> exercise that code:

Done.

> 0002:
> Looks good to me.

Cool.

> 0003:
> in accumulate_append_subpath(), but in get_singleton_append_subpath()
> there are only calls to lappend() and no list_concat(). Is that
> intentional? Do we also want to concatenate the newly pulled up
> child_append_relid_sets with the existing ones in
> get_singleton_append_subpath()?

Oh, good catch! Adjusted.

> In add_paths_to_append_rel():
>
> @@ -1785,13 +1790,16 @@ add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel,
> {
> Path *path = (Path *) lfirst(l);
> AppendPath *appendpath;
> + AppendPathInput append = {0};
> +
> + append.partial_subpaths = list_make1(path);
> + append.child_append_relid_sets = list_make1(rel->relids);
>
> Could you help me understand why we need to populate
> append.child_append_relid_sets here? I don’t see this child rel being
> pulled up at this point.

Oops, good point. Adjusted this, too.

> 0004:
> I’ve only read through the README and documentation so far; I’ll
> continue reviewing the code in 0004.

Thanks!

I plan to post an updated patch set shortly.

--
Robert Haas
EDB: http://www.enterprisedb.com