Horton

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

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Sutou Kouhei <kou@clear-code.com>
Cc: sawada.mshk@gmail.com, zhjwpku@gmail.com, andrew@dunslane.net, nathandbossart@gmail.com, pgsql-hackers@postgresql.org
Date: 2024-01-24T08:11:49Z
Lists: pgsql-hackers 
On Wed, Jan 24, 2024 at 02:49:36PM +0900, Sutou Kouhei wrote:
> For COPY TO:
> 
> 0001: This adds CopyToRoutine and use it for text/csv/binary
> formats. No implementation change. This just move codes.

10M without this change:

    format,elapsed time (ms)
    text,1090.763
    csv,1136.103
    binary,1137.141

10M with this change:

    format,elapsed time (ms)
    text,1082.654
    csv,1196.991
    binary,1069.697

These numbers point out that binary is faster by 6%, csv is slower by
5%, while text stays around what looks like noise range.  That's not
negligible.  Are these numbers reproducible?  If they are, that could
be a problem for anybody doing bulk-loading of large data sets.  I am
not sure to understand where the improvement for binary comes from by
reading the patch, but perhaps perf would tell more for each format?
The loss with csv could be blamed on the extra manipulations of the
function pointers, likely.
--
Michael

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.