ZhangHuiGui opened a new issue, #41233: URL: https://github.com/apache/arrow/issues/41233
### Describe the bug, including details regarding any error messages, version, and platform. Find from blow comment: https://github.com/apache/arrow/pull/41036#discussion_r1564538418 It's bug in grouper when set are_cols_in_encoding_order=false in below codes: https://github.com/apache/arrow/blob/2979d69a05cb16012da06baaa801a1849e9110ce/cpp/src/arrow/compute/row/grouper.cc#L582 It will cause the num_group different with `are_cols_in_encoding_order=true` condition. The encoder will sort columns by default, when we only set this compare args to false, the `CompareColumnsToRows`'s input `impl_ptr->encoder_.batch_all_cols(), impl_ptr->rows_,` are all sorted, but use the incorrect column_offset to access compared column: https://github.com/apache/arrow/blob/2979d69a05cb16012da06baaa801a1849e9110ce/cpp/src/arrow/compute/row/compare_internal.cc#L366-L369 ### Component(s) C++ -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
