Polars 2.0 ships with streaming and spill-to-disk enabled by default

Polars released version 2.0 on October 6, 2026. It says LazyFrame.collect now uses the streaming engine by default, while supported operations can spill to disk when memory use reaches roughly 80% of RAM. The release also adds a Map data type and expands SQL support. Polars notes that streaming does not guarantee row order for certain operations unless users set maintain_order=True; spill-to-disk support for joins and group-bys is still planned.