Github user cloud-fan commented on a diff in the pull request:

    https://github.com/apache/spark/pull/11673#discussion_r56599961
  
    --- Diff: 
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/Analyzer.scala
 ---
    @@ -1450,7 +1450,9 @@ object CleanupAliases extends Rule[LogicalPlan] {
             case c: CreateStructUnsafe if !stop =>
               stop = true
               c.copy(children = c.children.map(trimNonTopLevelAliases))
    -        case Alias(child, _) if !stop => child
    +        // Only eliminate aliases for named expressions, otherwise we may 
turn an `Alias` to a
    +        // normal expression and break the type requirement for it.
    +        case Alias(child: NamedExpression, _) if !stop => child
    --- End diff --
    
    how about we just check `if plan.pruducedAttributes.isEmpty`?


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