ozankabak commented on PR #5290: URL: https://github.com/apache/arrow-datafusion/pull/5290#issuecomment-1432533070
Not all built-in window functions are reversible. There is an indicator in the API called `get_reverse_expr` in the `WindowExpr` trait, which returns `None` if there is no equivalent reverse. For built-ins, this function calls `reverse_expr`, whose default value is `None`. Functions like `LEAD` and `LAG` override this to indicate reversibility, but `ROW_NUMBER` doesn't. -- 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]
