After merging your PR, Conbench analyzed the 4 benchmarking runs that have been run so far on merge-commit 45f562a.

Benchmarks with performance regressions

There was 1 possible performance regression, according to the lookback z-score method.

Benchmarks with regressions:

• Commit Run on amd64-m5-4xlarge-linux at 2025-07-11 10:28:11Z
  • partitioned-dataset-filter (R) with dataset=dataset-taxi-parquet, language=R, query=vignette

All benchmark runs analyzed:

• Commit Run on arm64-t4g-2xlarge-linux at 2025-07-11 14:20:21Z
• Commit Run on amd64-c6a-4xlarge-linux at 2025-07-11 09:05:34Z
• Commit Run on amd64-m5-4xlarge-linux at 2025-07-11 10:28:11Z
• Commit Run on test-mac-arm at 2025-07-11 23:08:20Z

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 2025-07-11 14:20:21Z
  • BM_DeltaBitPackingEncode_Int32_Wide (C++) with params=1024, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_DeltaBitPackingDecode_Int64_Wide (C++) with params=4096, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_DeltaBitPackingDecode_Int64_Wide (C++) with params=1024, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_DeltaBitPackingDecode_Int64_Fixed (C++) with params=4096, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_PlainDecodingSpacedByteArray (C++) with params=max-string-length:8/batch-size:512, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_DeltaBitPackingDecode_Int32_Fixed (C++) with params=4096, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_ByteStreamSplitEncode_Float_Scalar (C++) with params=1024, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_DeltaBitPackingDecode_Int64_Fixed (C++) with params=32768, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_ByteStreamSplitDecode_Int16_Neon (C++) with params=1024, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_DeltaBitPackingEncode_Int32_Wide (C++) with params=4096, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_DeltaBitPackingDecode_Int32_Narrow (C++) with params=4096, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_DeltaBitPackingDecode_Int64_Fixed (C++) with params=1024, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_DeltaBitPackingDecode_Int32_Wide (C++) with params=1024, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_PlainDecodingSpacedFloat (C++) with params=32768/10000, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_DeltaBitPackingDecode_Int32_Wide (C++) with params=65536, source=cpp-micro, suite=parquet-encoding-benchmark
  • GrouperWithMultiTypes (C++) with params="{int64}"/1024/100, source=cpp-micro, suite=arrow-compute-grouper-benchmark
  • BM_DeltaBitPackingDecode_Int32_Wide (C++) with params=4096, source=cpp-micro, suite=parquet-encoding-benchmark
  • BM_DeltaBitPackingEncode_Int32_Fixed (C++) with params=4096, source=cpp-micro, suite=parquet-encoding-benchmark