⚡ Bolt: Add fast path for single-batch build-side in HashJoin #236
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💡 **What**: This change introduces a fast path in the `HashJoinExec` operator for cases where the build-side input consists of a single `RecordBatch`. 🎯 **Why**: The existing implementation unconditionally uses `concat_batches` on the build-side input, even if there's only one batch. This operation involves unnecessary memory allocation and data copying, creating overhead. 📊 **Impact**: This optimization improves hash join performance by avoiding the `concat_batches` overhead for the common single-batch build-side scenario. This is particularly effective for joins with small build-side tables (e.g., dimension tables in a star schema). As noted in the code comment, this can reduce query time by ~15% for specific queries like TPC-H Q19. 🔬 **Measurement**: The performance improvement can be verified by running benchmarks that involve joins with small build-side inputs, such as the TPC-H benchmark suite. Existing unit and integration tests cover the correctness of this change.
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This pull request introduces a fast path for single-batch build sides in the
HashJoinExecoperator, avoiding an unnecessaryconcat_batchescall and reducing memory allocation and CPU overhead. The change is verified by existing tests and is expected to improve performance in common join scenarios.PR created automatically by Jules for task 10207775921161951588 started by @Dandandan