Polars 2.0 RC2 ships Map dtype, join-derived predicates and parquet scan optimizations
JeremyCMorgan · x · 2026-09-26
Polars 2.0.0-rc.2 is out with breaking changes: a new Map dtype, deprecated cut/qcut, Parquet ENUM now reads as String, removal of legacy POLARSSTREAMINGCHUNKSIZE, and updated 0-width input behavior. Performance work includes dynamic predicates for hash joins, predicates derived from join conditions, selectivity-ordered parquet predicate pushdown, float literals coerced to decimal instead of column casts, row-group splitting prep for Polars Cloud, and fixes for a TPCH OOM. Author urges testing pipelines against it now.
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