After merging your PR, Conbench analyzed the 3 benchmarking runs that have been run so far on merge-commit 5a71d2a.

Benchmarks with performance regressions

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

All benchmark runs analyzed:

• Commit Run on amd64-c6a-4xlarge-linux at 2026-01-28 02:25:28Z
• Commit Run on arm64-t4g-2xlarge-linux at 2026-01-28 02:59:48Z
• Commit Run on amd64-m5-4xlarge-linux at 2026-01-28 03:00:08Z

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 amd64-c6a-4xlarge-linux at 2026-01-28 02:25:28Z

  • ArrayArrayKernel (C++) with params=<Add, UInt8Type>/size:524288/inverse_null_proportion:100, source=cpp-micro, suite=arrow-compute-scalar-arithmetic-benchmark
  • UniqueInt64 (C++) with params=0, source=cpp-micro, suite=arrow-compute-vector-hash-benchmark
  • AllocateDeallocate (C++) with params=/size:65536/real_time/threads:1, source=cpp-micro, suite=arrow-memory-pool-benchmark
  • ArrayArrayKernel (C++) with params=<Subtract, UInt8Type>/size:524288/inverse_null_proportion:100, source=cpp-micro, suite=arrow-compute-scalar-arithmetic-benchmark
  • ArrayArrayKernel (C++) with params=<Subtract, UInt8Type>/size:524288/inverse_null_proportion:0, source=cpp-micro, suite=arrow-compute-scalar-arithmetic-benchmark
  • ArrayArrayKernel (C++) with params=<Add, UInt8Type>/size:524288/inverse_null_proportion:0, source=cpp-micro, suite=arrow-compute-scalar-arithmetic-benchmark

• Commit Run on arm64-t4g-2xlarge-linux at 2026-01-28 02:59:48Z

  • BitmapReaderSumWithOffset (C++) with params=2, source=cpp-micro, suite=arrow-bit-block-counter-benchmark