Horton

Re: Make COPY format extendable: Extract COPY TO format implementations

Junwang Zhao <zhjwpku@gmail.com>

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From: Junwang Zhao <zhjwpku@gmail.com>
To: Sutou Kouhei <kou@clear-code.com>
Cc: sawada.mshk@gmail.com, andrew@dunslane.net, michael@paquier.xyz, nathandbossart@gmail.com, pgsql-hackers@postgresql.org
Date: 2024-01-26T08:18:14Z
Lists: pgsql-hackers

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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

Commits

  1. Refactor Copy{From|To}GetRoutine() to use pass-by-reference argument.

  2. Refactor COPY FROM to use format callback functions.

  3. Refactor COPY TO to use format callback functions.

  4. Another try to fix BF failure introduced in commit ddd5f4f54a.

  5. Revert "Refactor CopyReadAttributes{CSV,Text}() to use a callback in COPY FROM"

  6. Improve COPY TO performance when server and client encodings match

  7. Simplify signature of CopyAttributeOutCSV() in copyto.c

  8. Revert "Refactor CopyAttributeOut{CSV,Text}() to use a callback in COPY TO"

  9. Refactor CopyAttributeOut{CSV,Text}() to use a callback in COPY TO

  10. Refactor CopyReadAttributes{CSV,Text}() to use a callback in COPY FROM

  11. Add progress reporting of skipped tuples during COPY FROM.

  12. pgbench: Add \syncpipeline

  13. meson: Make gzip and tar optional

  14. Export the external file reader used in COPY FROM as APIs.