DataFusion optimises the physical plan by interrogating operators through a dozen declarative methods — distribution requirements, ordering requirements, limit pushdown, …
A guided tour of DataFusion’s physical operators — the scan, the filter, the projection, the repartition, the joins, the aggregate, the sort and the window — and the trick in each.
A tour of the DataFusion configuration surface, grouped by what it controls — parallelism, pushdown, spilling, and the join/sort decisions — with the trade-off each knob implies.
DataFusion’s Parquet writer encodes row groups in parallel across columns, streams them to object storage in one pass, and — when the input plan is already ordered — records the …
A UDF’s Signature is three orthogonal promises: which types it accepts, how it coerces them, and whether its result is repeatable.