Hi, On Tue, 24 Feb 2026 at 07:44, Manni Wood <[email protected]> wrote: > > Hello! > > I ran some speed tests on Nazir's v10 SIMD-only patch. I'm a bit surprised at > the regression for x86 with wide rows for the 1/3rd special characters > scenarios. I'm hoping it's something I did wrong. If anyone else has numbers > to share, that would be excellent.
Thank you for doing this! I see similar regression on the wide & CSV 1/3 case by using your benchmark script. I didn't see this regression when I used my benchmark while sharing v9 [1]. +-------------+---------------------------+---------------------------+ | | Text | CSV | +-------------+-------------+-------------+-------------+-------------+ | WIDE TEST | None | 1/3 | None | 1/3 | +-------------+-------------+-------------+-------------+-------------+ | Master | 9996 | 10769 | 11548 | 13960 | +-------------+-------------+-------------+-------------+-------------+ | v10 | 8912 %-10.8 | 10902 %+1.2 | 8952 %-22.4 | 15123 %+8.3 | +-------------+-------------+-------------+-------------+-------------+ | | | | | | +-------------+-------------+-------------+-------------+-------------+ | | Text | | CSV | +-------------+-------------+-------------+-------------+-------------+ | NARROW TEST | None | 1/3 | None | 1/3 | +-------------+-------------+-------------+-------------+-------------+ | Master | 9441 | 9561 | 9734 | 9830 | +-------------+-------------+-------------+-------------+-------------+ | v10 | 9291 %-1.5 | 9504 -%0.5 | 9644 %-0.9 | 10078 %-2.4 | +-------------+-------------+-------------+-------------+-------------+ I will investigate this. However, please note that the current master includes the inlining commit (dc592a4155), which makes the COPY FROM faster. In my case, 1: current master without dc592a4155: 14400ms 2: current master: 13960ms (%3 improvement against #1) 3: current master + SIMD: 15123ms (%5 regression against #1 and %8 regression against #2) Is it possible for you to do a similar test? I mean dropping dc592a4155 from the current master and re-running the benchmark, that would be helpful. [1] https://postgr.es/m/CAN55FZ0MiFCgK26gRgE05a%3D_ggenkxDM8H%3DA2uTHpywczqt%3D-Q%40mail.gmail.com -- Regards, Nazir Bilal Yavuz Microsoft
