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

Hello,

On Wed, Feb 4, 2026, 6:38 AM Manni Wood <manni(dot)wood(at)enterprisedb(dot)com> wrote:

> The 0001-COPY-from-SIMD-v3-with-line_buf-periodic-refill.patch seems nice!
> On My x86 PC, it had the usual performance improvment of earlier patches,
> but the regression seemed more similar for both text and csv inputs.
> Unfortunately, the regression is about 2.5%, but maybe that is an
> acceptable worst-case for an improvement of 22% for text inputs and 33% for
> CSV inputs?
>
> The 0001-COPY-from-SIMD-v3-with-line_buf-periodic-refill.patch looks even
> better on my Raspberry Pi's arm processor: not only do we see a 22%
> improvement for text and an almost 34% improvement for CSV, even the
> worst-case scenarios show an almost 4% improvement for text and an 11.7%
> improvement for CSV.
>
> By comparison,
> the v5.1-0001-Simple-heuristic-for-SIMD-COPY-FROM.patch.patch's worst-case
> performance is poorer on both architectures.
>
> I'd be curious to know if anyone else can reproduces these
> numbers. 0001-COPY-from-SIMD-v3-with-line_buf-periodic-refill.patch seems
> like a real winner.
>
Thanks for the benchmark Manni, i suppose this is the same threshold as
patch has (4096 bytes), have you tried any bigger values for the threshold
?
Because i'm still expecting less l1d cache misses and execution times the
more we increase the threshold (relatively to l1d cache size per core).
As per my previous not-so-stable numbers 28KB wasn't too bad.

Regards,
Ayoub