lyne7-sc opened a new pull request, #25413:
URL: https://github.com/apache/datafusion/pull/25413
## Which issue does this PR close?
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- Closes #.
## Rationale for this change
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For `RightSemi` and `RightAnti` nested loop joins, each right row only needs
one match to determine whether it belongs in the result. Currently, matched
right rows continue participating in comparisons with subsequent left rows.
Skipping these comparisons can significantly reduce execution time when
matches are found early.
## What changes are included in this PR?
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- Add `RightExistenceProbe` to track matches and right-side candidates.
- Compact the right-side filter columns when at least half the candidates
have matched and more left rows remain.
- Stop probing the current right batch when all its rows have matched.
- Preserve matches in original right-row coordinates for output and spill
handling.
## What is the testing strategy for this PR?
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- Add unit tests for match tracking and candidate compaction.
- Add SQL coverage in `nested_loop_join_existence.slt` for
RightSemi/RightAnti joins, including NULLs, repeated matches, and multiple left
rows per probe.
- Extend `nested_loop_join_spill.slt` to cover RightSemi/RightAnti joins
across spilled left chunks.
## Are there any user-facing changes?
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No. This is an internal performance optimization.
## Benchmark results
| Case | Scenario | main | This PR | Time change |
|---|---|---:|---:|---:|
| Q15 | Right Semi, early matches | 307.659 | 0.365 | -99.88% |
| Q16 | Right Anti, early matches | 306.225 | 0.338 | -99.89% |
| Q18 | Right Semi, no matches | 7.964 | 7.728 | -2.95% |
| Q19 | Right Anti, no matches | 8.100 | 7.770 | -4.07% |
| Q20 | Right Semi, staged compaction | 56.082 | 7.182 | -87.19% |
| Q21 | Right Anti, staged compaction | 56.057 | 7.115 | -87.31% |
| Q22 | Right Semi, repeated 40% matches (4,096 left × 8,192 right) | 12.185
| 12.410 | +1.84% |
| Q23 | Right Anti, final-left-row matches with wide Utf8 | 0.305125 |
0.309042 | +1.28% |
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