lazy_coalesce_fallback_case_statement

Author: coderfender

spark/src/main/scala/org/apache/comet/serde/QueryPlanSerde.scala

@@ -1248,16 +1248,8 @@ object QueryPlanSerde extends Logging with CometExprShim {
           None
         }
 
-//      case a @ Coalesce(_) =>
-//        val branches = a.children.dropRight(1).map { child =>
-//          (IsNotNull(child), child)
-//        }
-//        val elseValue = Some(a.children.last)
-//
-//        exprToProtoInternal(CaseWhen(branches, elseValue), inputs, binding)
-      //
-      //        val exprChildren = a.children.map(exprToProtoInternal(_, inputs, binding))
-      //        scalarFunctionExprToProto("coalesce", exprChildren: _*)
+//  DataFusion coalesce doesnt perform lazy evaluation. Falling back to CASE statement until upstream data fusion issue is fixed
+//  https://github.com/apache/datafusion/pull/17357/files
 
       case c @ (CaseWhen(_, _) | Coalesce(_)) =>
         val (finalBranches, finalElse) = c match {