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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 …
DataFusion’s null-aware hash join tracks NOT IN’s three-valued logic with per-build-row bitmaps and a separate hash table of NULL-valued build rows, because the answer depends on …
DataFusion implements ASOF join as a forward-only merge over two sorted inputs, keeping exactly one candidate right row per equality group and replacing it as better matches …
A dictionary column is a pre-built hash cache: DataFusion hashes each distinct dictionary value once, scatters those hashes to the keys, and memoizes value-index to group-slot so …
Constant folding happens in the logical optimizer via a dummy-batch evaluator, algebraic rules fire in a fixpoint loop, and casts are unwrapped into the literal when the conversion …