Re: Extend COPY FROM with HEADER to skip multiple lines - Mailing list pgsql-hackers

On Thu, Jul 3, 2025 at 3:32 PM Fujii Masao <masao.fujii@oss.nttdata.com> wrote:
>
>
>
> On 2025/07/03 11:08, Shinya Kato wrote:
> > On Wed, Jul 2, 2025 at 4:48 PM Fujii Masao <masao.fujii@oss.nttdata.com> wrote:
> >
> >>>> Regarding the documentation, how about explicitly stating that when MATCH is specified, only
> >>>> the first line is skipped? While this may seem obvious, it’s worth clarifying, as the semantics
> >>>> of the HEADER option have become a bit more complex with this change.
> >>>
> >>> Agreed.  I have updated the documentation as follows:
> >>>
> >>> +      lines are discarded.  If the option is set to <literal>MATCH</literal>,
> >>> +      the number and names of the columns in the header line must exactly
> >>> +      match those of the table and, in order, after which the header line is
> >>> +      discarded;  otherwise an error is raised.  The <literal>MATCH</literal>
> >>
> >> How about making the wording a bit clearer? For example:
> >>
> >>       If set to MATCH, the first line is discarded, and it must contain column names that
> >>       exactly match the table's columns, in both number and order; otherwise, an error is raised.
> >
> > Thank you for the review. I fixed it.
>
> Thanks for updating the patch! I've pushed the patch.
>
>
> >> Also, the phrase "if this option is set to..." is repeated three times in the current text.
> >> For the second and third instances, we could simplify it to just "if set to...".
> >
> > Agreed. However, for the sake of symmetry between "On output" and "On
> > input" and to maintain clarity between the paragraphs, I have omitted
> > "this option is" from the "On input" paragraph only.
>
> Yes, I agree that's better.
>
> Regards,
>
> --
> Fujii Masao
> NTT DATA Japan Corporation
>

Thank you for pushing!

--
Best regards,
Shinya Kato
NTT OSS Center