⚡ Bolt: optimize single-batch build side in hash join#274
⚡ Bolt: optimize single-batch build side in hash join#274
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This PR implements a performance optimization in `HashJoinExec` for the common case where the build side consists of a single `RecordBatch`. 💡 What: - Added a fast path in `try_create_array_map` and `collect_left_input` for single-batch build-side inputs. - Bypasses `concat_batches` and redundant `evaluate_expressions_to_arrays` calls. 🎯 Why: - Previously, join expressions were evaluated on individual batches to build the hash map, then all batches were concatenated into one, and expressions were re-evaluated on the concatenated batch. - For single batches, this resulted in exactly 2x the necessary CPU work for expression evaluation and an unnecessary data copy in `concat_batches`. 📊 Impact: - Reduces CPU usage for the build phase of hash joins with small build sides. - Improves memory efficiency by avoiding temporary allocations in `concat_batches`. 🔬 Measurement: - Verified that all 355 join tests in `datafusion-physical-plan` pass. - Logic follows existing deterministic LIFO insertion order for hash map collision chains. Co-authored-by: Dandandan <163737+Dandandan@users.noreply.github.com>
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Implemented a fast path for single-batch build side in
HashJoinExecto avoid redundant expression evaluations andconcat_batches. This improves performance and efficiency for joins with small build sides.PR created automatically by Jules for task 4292392479032325427 started by @Dandandan