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

Hello,

I ran some long benchmarks on this, and I got stable results across
multiple runs (few milliseconds difference)

This is on an Intel I7-1255U CPU with:
sudo cpupower frequency-set --governor=performance
sudo cpupower idle-set -D 0
echo "1" | sudo tee /sys/devices/system/cpu/intel_pstate/no_turbo

WIDE (500k rows)

TXT | none
Master avg: 22,183 ms
New avg: 20,435 ms
Improvement: -7.88%

CSV | none
Master avg: 26,737 ms
New avg: 24,625 ms
Improvement: -7.90%

TXT | escape
Master avg: 26,720 ms
New avg: 23,658 ms
Improvement: -11.46%

CSV | quote
Master avg: 35,961 ms
New avg: 33,317 ms
Improvement: -7.35%

--------------------------------------

NARROW (1.5M rows)

TXT | none
Master avg: 2,220 ms
New avg: 2,125 ms
Improvement: -4.28%

CSV | none
Master avg: 2,330 ms
New avg: 2,145 ms
Improvement: -7.92%

TXT | escape
Master avg: 2,425 ms
New avg: 2,187 ms
Improvement: -9.79%

CSV | quote
Master avg: 2,272 ms
New avg: 2,253 ms
Improvement: -0.85%

No regressions as expected, overall this looks good.

Regards,

Ayoub

On Thu, Feb 19, 2026 at 10:01 AM Nazir Bilal Yavuz <byavuz81(at)gmail(dot)com>
wrote:

> Hi,
>
> On Thu, 19 Feb 2026 at 07:02, Manni Wood <manni(dot)wood(at)enterprisedb(dot)com>
> wrote:
> >
> > I took some time tonight to apply v8 to the latest master (759b03b2) on
> my x86 tower and arm raspberry pi 5.
> >
> > Here are the results, using both narrow columns and the wider columns
> we've been using througout:
> >
> > x86 master NARROW
> > TXT : 2587.642000 ms
> > CSV : 2621.759000 ms
> > TXT with 1/3 escapes: 2707.933500 ms
> > CSV with 1/3 quotes: 3254.896500 ms
> >
> > x86 v8 NARROW
> > TXT : 2488.655250 ms 3.825365% improvement
> > CSV : 2628.818000 ms -0.269247% regression
> > TXT with 1/3 escapes: 2615.522000 ms 3.412621% improvement
> > CSV with 1/3 quotes: 3446.368000 ms -5.882568% regression
> >
> > x86 master WIDE
> > TXT : 30583.229500 ms
> > CSV : 35054.533500 ms
> > TXT with 1/3 escapes: 32767.421500 ms
> > CSV with 1/3 quotes: 44214.163500 ms
> >
> > x86 v8 WIDE
> > TXT : 26527.494250 ms 13.261305% improvement
> > CSV : 33364.443750 ms 4.821316% improvement
> > TXT with 1/3 escapes: 29320.648000 ms 10.518904% improvement
> > CSV with 1/3 quotes: 42334.074750 ms 4.252232% improvement
> >
> >
> >
> > arm master NARROW
> > TXT : 1999.401000 ms
> > CSV : 2081.610750 ms
> > TXT with 1/3 escapes: 2053.230250 ms
> > CSV with 1/3 quotes: 2431.608750 ms
> >
> > arm v8 NARROW
> > TXT : 1981.663750 ms 0.887128% improvement
> > CSV : 2023.892500 ms 2.772769% improvement
> > TXT with 1/3 escapes: 2004.215250 ms 2.387214% improvement
> > CSV with 1/3 quotes: 2616.872750 ms -7.618989% regression
> >
> > arm master WIDE
> > TXT : 9120.731750 ms
> > CSV : 11114.478250 ms
> > TXT with 1/3 escapes: 10338.124500 ms
> > CSV with 1/3 quotes: 13404.430250 ms
> >
> > arm v8 WIDE
> > TXT : 8430.090750 ms 7.572210% improvement
> > CSV : 10115.135500 ms 8.991360% improvement
> > TXT with 1/3 escapes: 9624.383500 ms 6.903970% improvement
> > CSV with 1/3 quotes: 12331.714000 ms 8.002699% improvement
>
> Thank you for the results, they are interesting. I didn't expect to
> see any regression for this benchmark. Also, I would expect the
> non-special character cases and the 1/3 special character cases to
> perform similarly, since we are not using SIMD for this benchmark.
>
> I noticed that the timings in your narrow benchmark (both x86 and ARM)
> are quite short. Would it be possible to extend the test so that the
> total runtime is closer to ~10,000 ms? That might give us more stable
> results.
>
> Here is my benchmark with using your script:
>
> WIDE: Total 500000 lines and each line is 4096 bytes.
> NARROW: Total 1500000 lines and each line is 2-4 bytes (`"A""A"` and
> `A\\A`).
>
>
> +---------+---------------+---------------+---------------+----------------+
> | WIDE | TXT None | TXT 1/3 | CSV None | CSV 1/3
> |
>
> +---------+---------------+---------------+---------------+----------------+
> | master | 10512 | 11133 | 12241 | 14321
> |
>
> +---------+---------------+---------------+---------------+----------------+
> | patched | 10000 (-%4.8) | 10804 (-%2.9) | 11571 (-%5.4) | 14008 (-%2.18)
> |
>
> +---------+---------------+---------------+---------------+----------------+
> | | | | |
> |
>
> +---------+---------------+---------------+---------------+----------------+
> | NARROW | | | |
> |
>
> +---------+---------------+---------------+---------------+----------------+
> | master | 9702 | 9745 | 9784 | 10149
> |
>
> +---------+---------------+---------------+---------------+----------------+
> | patched | 9344 (-%3.6) | 9477 (-%2.7) | 9439 (-%3.5) | 9751 (-%3.9)
> |
>
> +---------+---------------+---------------+---------------+----------------+
>
> The results look promising to me.
>
> --
> Regards,
> Nazir Bilal Yavuz
> Microsoft
>