[GitHub] [arrow-datafusion] ozankabak commented on a diff in pull request #5772: Change required input ordering API

["ozankabak (via GitHub)" <gi...@apache.org>]

ozankabak commented on code in PR #5772:
URL: https://github.com/apache/arrow-datafusion/pull/5772#discussion_r1152375908


##########
datafusion/core/src/physical_plan/windows/mod.rs:
##########
@@ -187,6 +188,30 @@ fn create_built_in_window_expr(
     })
 }
 
+pub(crate) fn calc_requirements(
+    partition_by_exprs: &[Arc<dyn PhysicalExpr>],
+    orderby_sort_exprs: &[PhysicalSortExpr],
+) -> Option<Vec<PhysicalSortRequirement>> {
+    let mut sort_reqs = vec![];
+    for partition_by in partition_by_exprs {
+        sort_reqs.push(PhysicalSortRequirement {
+            expr: partition_by.clone(),
+            options: None,
+        });
+    }
+    for PhysicalSortExpr { expr, options } in orderby_sort_exprs {
+        let contains = sort_reqs.iter().any(|e| expr.eq(&e.expr));
+        if !contains {
+            sort_reqs.push(PhysicalSortRequirement {
+                expr: expr.clone(),
+                options: Some(*options),
+            });
+        }
+    }
+    // Convert empty result to None. Otherwise wrap result inside Some()
+    (!sort_reqs.is_empty()).then_some(sort_reqs)
+}
+

Review Comment:
   Since `ORDER BY` is local to each partition, I think we are fine here. There is some related discussion here: https://stackoverflow.com/questions/50364818/using-the-same-column-in-partition-by-and-order-by-with-dense-rank
   
   I am still taking a note to remind us that we may want to revisit this if we find out information indicating otherwise.



-- 
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: github-unsubscribe@arrow.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org