[GitHub] [spark] cloud-fan commented on a diff in pull request #42778: [SPARK-45055] [SQL] Do not transpose windows if they conflict on ORDER BY / PROJECT clauses

["cloud-fan (via GitHub)" <gi...@apache.org>]

cloud-fan commented on code in PR #42778:
URL: https://github.com/apache/spark/pull/42778#discussion_r1314425064


##########
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/Optimizer.scala:
##########
@@ -1305,11 +1305,20 @@ object TransposeWindow extends Rule[LogicalPlan] {
     }
   }
 
+  // Returns false if the parent 'w1' window function order by any of the window
+  // expressions produced by 'w2'.
+  private def compatibleOrderBy(w1: Window, w2: Window): Boolean = {
+    val childWindowExprs = w2.windowExpressions.map(x => x.toAttribute)
+    val parentOrder = w1.orderSpec.flatMap(x => x.references)
+    childWindowExprs.intersect(parentOrder).isEmpty
+  }
+
   private def windowsCompatible(w1: Window, w2: Window): Boolean = {
     w1.references.intersect(w2.windowOutputSet).isEmpty &&

Review Comment:
   I'm a bit confused. Isn't the ORDER BY column part of `Window#references`? The code here should prevent this bug from happening IIUC.



-- 
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: reviews-unsubscribe@spark.apache.org

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


---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org