Re: Make COPY format extendable: Extract COPY TO format implementations - Mailing list pgsql-hackers

On Thu, Jan 25, 2024 at 4:52 PM Sutou Kouhei <kou@clear-code.com> wrote:
>
> Hi,
>
> In <CAD21AoALxEZz33NpcSk99ad_DT3A2oFNMa2KNjGBCMVFeCiUaA@mail.gmail.com>
>   "Re: Make COPY format extendable: Extract COPY TO format implementations" on Thu, 25 Jan 2024 13:36:03 +0900,
>   Masahiko Sawada <sawada.mshk@gmail.com> wrote:
>
> >                 I've experimented with a similar optimization for csv
> > and text format; have different callbacks for text and csv format and
> > remove "if (cstate->opts.csv_mode)" branches. I've attached a patch
> > for that. Here are results:
> >
> > HEAD w/ 0001 patch + remove branches:
> > binary 2824.502 ms
> > text 2715.264 ms
> > csv 2803.381 ms
> >
> > The numbers look better now. I'm not sure these are within a noise
> > range but it might be worth considering having different callbacks for
> > text and csv formats.
>
> Wow! Interesting. I tried the approach before but I didn't
> see any difference by the approach. But it may depend on my
> environment.
>
> I'll import the approach to the next patch set so that
> others can try the approach easily.
>
>
> Thanks,
> --
> kou

Hi Kou-san,

In the current implementation, there is no way that one can check
incompatibility
options in ProcessCopyOptions, we can postpone the check in CopyFromStart
or CopyToStart, but I think it is a little bit late. Do you think
adding an extra
check for incompatible options hook is acceptable (PFA)?


--
Regards
Junwang Zhao