Horton

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

Nazir Bilal Yavuz <byavuz81@gmail.com>

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From: Nazir Bilal Yavuz <byavuz81@gmail.com>
To: KAZAR Ayoub <ma_kazar@esi.dz>
Cc: Andrew Dunstan <andrew@dunslane.net>, Shinya Kato <shinya11.kato@gmail.com>, pgsql-hackers@postgresql.org
Date: 2025-10-18T20:01:41Z
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 →

  1. Optimize COPY FROM (FORMAT {text,csv}) using SIMD.

  2. Speedup COPY FROM with additional function inlining.

  3. doc: Fix incorrect wording for --file in pg_dump

Hi,

On Sat, 18 Oct 2025 at 21:46, KAZAR Ayoub <ma_kazar@esi.dz> wrote:
>
> Hello,
>
> I’ve rebenchmarked the new heuristic patch, We still have the previous improvements ranging from 15% to 30%. For regressions i see at maximum 3% or 4% in the worst case, so this is solid.

Thank you so much for doing this! The results look nice, do you think
there are any other benchmarks that might be interesting to try?

> I'm also trying the idea of doing SIMD inside quotes with prefix XOR using carry less multiplication avoiding the slow path in all cases even with weird looking input, but it needs to take into consideration the availability of PCLMULQDQ instruction set with <wmmintrin.h> and here we go, it quickly starts to become dirty OR we can wait for the decision to start requiring x86-64-v2 or v3 which has SSE4.2 and AVX2.

I can not quite picture this, would you mind sharing a few examples or patches?

-- 
Regards,
Nazir Bilal Yavuz
Microsoft