Thanks for your patience. Conbench analyzed the 4 benchmarking runs that have been run so far on PR commit dd3ec0d.

Benchmarks with performance regressions

There were 19 possible performance regressions, according to the lookback z-score method.

Benchmarks with regressions:

• Pull Request Run on amd64-c6a-4xlarge-linux at 2025-11-28 15:12:47Z

  • BM_UnpackUint32 (C++) with params=DynamicUnaligned/20/64, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_DeltaLengthDecodingByteArray (C++) with params=max-string-length:8/batch-size:2048, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_UnpackUint32 (C++) with params=Avx2Unaligned/20/64, source=cpp-micro, suite=arrow-bpacking-benchmark
  • ReadLevels_BitPack (C++) with params=MaxLevel:3/NumLevels:8096/BatchSize:1024/LevelRepeatCount:1, source=cpp-micro, suite=parquet-column-reader-benchmark
  • BM_UnpackUint64 (C++) with params=ScalarUnaligned/47/64, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_DeltaDecodingByteArray (C++) with params=max-string-length:64/batch-size:2048/prefixed-percent:90, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_UnpackUint16 (C++) with params=ScalarUnaligned/13/64, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_DeltaDecodingByteArray (C++) with params=max-string-length:64/batch-size:2048/prefixed-percent:99, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_UnpackUint32 (C++) with params=DynamicAligned/20/64, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint16 (C++) with params=ScalarUnaligned/2/64, source=cpp-micro, suite=arrow-bpacking-benchmark
  • ReadLevels_BitPack (C++) with params=MaxLevel:3/NumLevels:8096/BatchSize:1024/LevelRepeatCount:7, source=cpp-micro, suite=parquet-column-reader-benchmark

• Pull Request Run on amd64-m5-4xlarge-linux at 2025-11-28 15:27:18Z

  • BM_UnpackUint16 (C++) with params=Avx2Unaligned/13/64, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint32 (C++) with params=ScalarUnaligned/2/64, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint32 (C++) with params=ScalarUnaligned/1/64, source=cpp-micro, suite=arrow-bpacking-benchmark
  • BM_UnpackUint32 (C++) with params=Avx2Unaligned/20/64, source=cpp-micro, suite=arrow-bpacking-benchmark

• Pull Request Run on test-mac-arm at 2025-11-28 17:29:13Z

  • BM_PlainDecodingSpacedBoolean (C++) with params=32768/1, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_PlainDecodingBoolean (C++) with params=65536, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_PlainDecodingBoolean (C++) with params=32768, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_PlainDecodingSpacedBoolean (C++) with params=32768/100, source=cpp-micro, suite=parquet-encoding-benchmark

All benchmark runs analyzed:

• Pull Request Run on amd64-c6a-4xlarge-linux at 2025-11-28 15:12:47Z
• Pull Request Run on amd64-m5-4xlarge-linux at 2025-11-28 15:27:18Z
• Pull Request Run on arm64-t4g-2xlarge-linux at 2025-11-28 15:39:43Z
• Pull Request Run on test-mac-arm at 2025-11-28 17:29:13Z