Horton

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

Sutou Kouhei <kou@clear-code.com>

View thread View on postgr.es
From: Sutou Kouhei <kou@clear-code.com>
To: sawada.mshk@gmail.com
Cc: michael@paquier.xyz, zhjwpku@gmail.com, andrew@dunslane.net, nathandbossart@gmail.com, pgsql-hackers@postgresql.org
Date: 2024-01-10T06:40:28Z
Lists: pgsql-hackers 
Hi,

In <CAD21AoC_dhfS97DKwTL+2nvgBOYrmN9XVYrE8w2SuDgghb-yzg@mail.gmail.com>
  "Re: Make COPY format extendable: Extract COPY TO format implementations" on Wed, 10 Jan 2024 15:33:22 +0900,
  Masahiko Sawada <sawada.mshk@gmail.com> wrote:

>> We can use the satic const struct approach by choosing one
>> of the followings:
>>
>> ...
>>
>> 4. ... other idea?
> 
> It's a just idea but the fourth idea is to provide a convenient macro
> to make it easy to construct the CopyFormatRoutine. For example,
> 
> #define COPYTO_ROUTINE(...) (Node *) &(CopyToFormatRoutine) {__VA_ARGS__}
> 
> static const CopyFormatRoutine testfmt_copyto_handler = {
>     .type = T_CopyFormatRoutine,
>     .is_from = true,
>     .routine = COPYTO_ROUTINE (
>         .start_fn = testfmt_copyto_start,
>         .onerow_fn = testfmt_copyto_onerow,
>         .end_fn = testfmt_copyto_end
>         )
> };
> 
> Datum
> copy_testfmt_handler(PG_FUNCTION_ARGS)
> {
>     PG_RETURN_POINTER(& testfmt_copyto_handler);
> }

Interesting. But I feel that it introduces another (a bit)
tricky mechanism...

BTW, we also need to set .type:

     .routine = COPYTO_ROUTINE (
         .type = T_CopyToFormatRoutine,
         .start_fn = testfmt_copyto_start,
         .onerow_fn = testfmt_copyto_onerow,
         .end_fn = testfmt_copyto_end
         )


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.