Re: [PATCH] Add error hints for invalid COPY options

On Mon, Nov 24, 2025 at 11:56:34AM -0800, Masahiko Sawada wrote:
> On Sat, Nov 22, 2025 at 8:33 PM Sugamoto Shinya <shinya34892(at)gmail(dot)com> wrote:
>> This follows the pattern already used elsewhere in PostgreSQL for providing
>> helpful error hints to users.
>
> Given we have 15 COPY options now, it sounds like a reasonable idea.
>
> One concern about the patch is that when adding a new COPY option, we
> could miss updating valid_copy_options list, resulting in providing a
> wrong suggestion. I think we can consider refactoring the COPY option
> handling so that we check the given option is a valid name or not by
> checking valid_copy_options array and then process the option value.

+1. Ideally, folks wouldn't need to update a separate list when adding new
options.

>> Additionally, this patch corrects a misleading comment for the
>> convert_selectively option. The comment stated it was "not-accessible-from-SQL",
>> but actualy it has been accessible from SQL due to PostgreSQL's generic option parser.
>> The updated comment clarifies that while technically accessible, it's intended for
>> internal use and not recommended for end-user use due to potential data loss.
>
> Hmm, I'm not sure the proposed comment improves the clarification.
> It's essentially non-accessible from SQL since we cannot provide a
> valid value for convert_selectively from SQL commands.

Yeah, I'd leave it alone, at least for this patch.

--
nathan