Re: Speed up COPY FROM text/CSV parsing using SIMD

Nazir Bilal Yavuz <byavuz81@gmail.com>

From: Nazir Bilal Yavuz <byavuz81@gmail.com>

To: KAZAR Ayoub <ma_kazar@esi.dz>

Cc: Shinya Kato <shinya11.kato@gmail.com>, pgsql-hackers@postgresql.org

Date: 2025-08-19T14:14:54Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Optimize COPY FROM (FORMAT {text,csv}) using SIMD.
- e0a3a3fd5361 19 (unreleased) landed
Speedup COPY FROM with additional function inlining.
- dc592a41557b 19 (unreleased) landed
doc: Fix incorrect wording for --file in pg_dump
- 07961ef86625 19 (unreleased) cited

Hi,

On Tue, 19 Aug 2025 at 15:33, Nazir Bilal Yavuz <byavuz81@gmail.com> wrote:
>
> I am able to reproduce the regression you mentioned but both
> regressions are %20 on my end. I found that (by experimenting) SIMD
> causes a regression if it advances less than 5 characters.
>
> So, I implemented a small heuristic. It works like that:
>
> - If advance < 5 -> insert a sleep penalty (n cycles).

'sleep' might be a poor word choice here. I meant skipping SIMD for n
number of times.

-- 
Regards,
Nazir Bilal Yavuz
Microsoft