DuckDB 2.0 alpha reads Parquet and CSV from S3 2x to 3x faster, with zero query changes.
1.5: each worker downloads, waits, decodes, repeats.
2.0: a download pool fetches ahead, workers only decode.
Same laptop, same query: 18.8 s to 7.7 s. On by default.
Full numbers, plus recursive CTEs and VARIANT: