From 872ef99987de0ed25c2e78a5347a2b18be1adc4b Mon Sep 17 00:00:00 2001
From: Marek Novotny <mn.mikke@gmail.com>
Date: Tue, 17 Jul 2018 11:50:18 +0200
Subject: [PATCH] [SPARK-24305][SQL][FOLLOWUP] Making fields used in eval
 lazy-evaluated (Concat, MapConcat)

---
 .../spark/sql/catalyst/expressions/collectionOperations.scala | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/collectionOperations.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/collectionOperations.scala
index 2345037ee7376..2b61261fb3e73 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/collectionOperations.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/collectionOperations.scala
@@ -516,7 +516,7 @@ case class MapConcat(children: Seq[Expression]) extends ComplexTypeMergingExpres
     }
   }
 
-  override def dataType: MapType = {
+  @transient override lazy val dataType: MapType = {
     if (children.isEmpty) {
       MapType(StringType, StringType)
     } else {
@@ -2224,7 +2224,7 @@ case class Concat(children: Seq[Expression]) extends ComplexTypeMergingExpressio
     }
   }
 
-  override def dataType: DataType = {
+  @transient override lazy val dataType: DataType = {
     if (children.isEmpty) {
       StringType
     } else {