DataFusion records cheap atomic metrics per operator partition, measures only the time spent inside poll(), and renders the annotated plan after the query finishes — so EXPLAIN …
DataFusion’s hash join inserts the build side in reverse order into a LIFO hash table, so the chain head is always the earliest matching row and the join output preserves the build …
DataFusion borrows the ambient Tokio runtime, funnels every spawn through a cancel-safe wrapper, and runs CPU work inline with cooperative yields instead of spawn_blocking.
DataFusion’s symmetric hash join hashes both streams, lets each side probe the other’s table, and prunes rows that can no longer match using interval arithmetic — trading memory …