tl;dr: Polars 2.0 ships with streaming/out-of-core execution enabled by default (spilling to disk at ~80% RAM), first-class SQL support, and a new Map dtype backed by Arrow's MapType. In TPC-H and TPC-DS benchmarks on AWS c7a instances, Polars outperforms DuckDB 1.5.6, DuckDB 2.0 alpha, and DataFusion on nearly all queries, though it has scaling overhead at 192 threads. The release also tightens strictness around dtypes and schema validation to catch errors earlier, which the team pitches as useful for AI-driven iteration.