Is it worth adding Assert(false) for unknown paths in print_path()?

On 2023-Sep-29, David Rowley wrote:

In [1] Andrey highlighted that I'd forgotten to add print_path()
handling for TidRangePaths in bb437f995.

I know the OPTIMIZER_DEBUG code isn't exactly well used. I never
personally use it and I work quite a bit in the planner, however, if
we're keeping it, I thought maybe we might get the memo of missing
paths a bit sooner if we add an Assert(false) in the default cases.

Is the attached worthwhile?

Hmm, if we had a buildfarm animal with OPTIMIZER_DEBUG turned on, then I
agree it would catch the omission quickly.

--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/
"¿Cómo puedes confiar en algo que pagas y que no ves,
y no confiar en algo que te dan y te lo muestran?" (Germán Poo)

David Rowley <dgrowleyml@gmail.com> writes:

In [1] Andrey highlighted that I'd forgotten to add print_path()
handling for TidRangePaths in bb437f995.

I know the OPTIMIZER_DEBUG code isn't exactly well used. I never
personally use it and I work quite a bit in the planner, however, if
we're keeping it, I thought maybe we might get the memo of missing
paths a bit sooner if we add an Assert(false) in the default cases.

FWIW, I'd argue for dropping print_path rather than continuing to
maintain it. I never use it, finding pprint() to serve the need
better and more reliably. However, assuming that we keep it ...

Is the attached worthwhile?

... I think this is actually counterproductive. It will certainly
not help draw the notice of anyone who wouldn't otherwise pay
attention to print_path. Also, observe the extremely longstanding
policy decision in outNode's default: case:

/*
* This should be an ERROR, but it's too useful to be able to
* dump structures that outNode only understands part of.
*/
elog(WARNING, "could not dump unrecognized node type: %d",
(int) nodeTag(obj));
break;

The same argument applies to print_path, I should think.

regards, tom lane

On Fri, 29 Sept 2023 at 03:23, Tom Lane <tgl@sss.pgh.pa.us> wrote:

FWIW, I'd argue for dropping print_path rather than continuing to
maintain it. I never use it, finding pprint() to serve the need
better and more reliably.

Then perhaps we just need to open a thread with an appropriate subject
to check if anyone finds it useful and if we don't get any response
after some number of weeks, just remove it from master.

David