Github user ueshin commented on a diff in the pull request:

    https://github.com/apache/spark/pull/21073#discussion_r199374458
  
    --- Diff: 
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/TypeCoercion.scala
 ---
    @@ -551,6 +551,36 @@ object TypeCoercion {
               case None => s
             }
     
    +      case m @ MapConcat(children) if children.forall(c => 
MapType.acceptsType(c.dataType)) &&
    +        !haveSameType(children) =>
    +        val keyTypes = 
children.map(_.dataType.asInstanceOf[MapType].keyType)
    --- End diff --
    
    Can't we do the same thing as the `Concat` does?
    
    ```scala
    val types = children.map(_.dataType)
    findWiderCommonType(types) match {
      case Some(finalDataType) => MapConcat(children.map(Cast(_, 
finalDataType)))
      case None => m
    }
    ```


---

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

Reply via email to