Horton

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

Sutou Kouhei <kou@clear-code.com>

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From: Sutou Kouhei <kou@clear-code.com>
To: zhjwpku@gmail.com
Cc: sawada.mshk@gmail.com, michael@paquier.xyz, pgsql-hackers@postgresql.org
Date: 2025-01-23T09:09:29Z
Lists: pgsql-hackers 
Hi,

In <CAEG8a3+-3fAmiwD5NmE7W4j5-=HLs2OEexQNW9-fB=j=mdxgDQ@mail.gmail.com>
  "Re: Make COPY format extendable: Extract COPY TO format implementations" on Fri, 29 Nov 2024 10:15:04 +0800,
  Junwang Zhao <zhjwpku@gmail.com> wrote:

> This thread and [1] thread are kind of interleaved, I chose this thread
> to share the numbers because I think this feature should be committed
> first and then adapt the *copy to json* as a contrib module.

I agree with you.

> Committers on this thread seem worried about the performance
> drawback, so what I tried to do is that *if 2 is slightly worse than 1,
> but better than 3*, then we can commit 2 first, but I did not get
> the expected number.

Could you break down which patch in the v13 patch set[1]
affected? If we can find which change improves performance,
we can use the approach in this patch set too.

[1]: https://www.postgresql.org/message-id/CACJufxH8J0uD-inukxAmd3TVwt-b-y7d7hLGSBdEdLXFGJLyDA%40mail.gmail.com


Thanks,
-- 
kou

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.