After merging your PR, Conbench analyzed the 3 benchmarking runs that have been run so far on merge-commit dbbf7cf.

Benchmarks with performance regressions

There were 0 possible performance regressions, according to the lookback z-score method.

All benchmark runs analyzed:

• Commit Run on arm64-t4g-2xlarge-linux at 2026-03-09 11:08:45Z
• Commit Run on amd64-c6a-4xlarge-linux at 2026-03-09 10:39:09Z
• Commit Run on amd64-m5-4xlarge-linux at 2026-03-09 11:08:46Z

Unstable benchmarks with performance regressions

The following benchmark results indicate a possible performance regression, but are known to sometimes produce false positives when applying the lookback z-score analysis.

• Commit Run on arm64-t4g-2xlarge-linux at 2026-03-09 11:08:45Z

  • BitBlockCounterFourWordsSum (C++) with params=512, source=cpp-micro, suite=arrow-bit-block-counter-benchmark
  • BitBlockCounterFourWordsSum (C++) with params=4096, source=cpp-micro, suite=arrow-bit-block-counter-benchmark
  • ResolveManyUInt16Random (C++) with params=chunked_array_length:65535/num_chunks:10000/num_indices:32764, source=cpp-micro, suite=arrow-chunk-resolver-benchmark
  • BitBlockCounterSum (C++) with params=65536, source=cpp-micro, suite=arrow-bit-block-counter-benchmark
  • BitBlockCounterSumWithOffset (C++) with params=32768, source=cpp-micro, suite=arrow-bit-block-counter-benchmark
  • BitmapReaderSumWithOffset (C++) with params=4096, source=cpp-micro, suite=arrow-bit-block-counter-benchmark
  • BitBlockCounterSumWithOffset (C++) with params=4096, source=cpp-micro, suite=arrow-bit-block-counter-benchmark

• Commit Run on amd64-c6a-4xlarge-linux at 2026-03-09 10:39:09Z

  • BM_UnpackUint64 (C++) with params=Avx2Unaligned/1/256, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=DynamicUnaligned/8/512, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=DynamicUnaligned/2/512, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=Avx2Unaligned/1/32, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=DynamicUnaligned/2/128, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=DynamicUnaligned/1/512, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=DynamicAligned/1/128, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=Avx2Unaligned/1/128, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=DynamicUnaligned/1/128, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=DynamicUnaligned/1/256, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=DynamicAligned/2/512, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=Avx2Unaligned/8/512, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=Avx2Unaligned/1/512, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=DynamicAligned/2/128, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=DynamicAligned/1/32, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=DynamicAligned/1/512, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=DynamicAligned/1/256, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint64 (C++) with params=DynamicUnaligned/1/32, source=cpp-micro, suite=arrow-bpacking-benchmark

• Commit Run on amd64-m5-4xlarge-linux at 2026-03-09 11:08:46Z

  • BM_UnpackUint32 (C++) with params=DynamicUnaligned/20/256, source=cpp-micro, suite=arrow-bpacking-benchmark