SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Function overlay (children 1)
     ExpressionList (children 3)
      Function materialize (children 1)
       ExpressionList (children 1)
        Literal \'Spark SQL\'
      Literal \'_\'
      Function materialize (children 1)
       ExpressionList (children 1)
        Literal UInt64_6
    Function overlayUTF8 (children 1)
     ExpressionList (children 3)
      Function materialize (children 1)
       ExpressionList (children 1)
        Literal \'Spark SQL和CH\'
      Literal \'_\'
      Function materialize (children 1)
       ExpressionList (children 1)
        Literal UInt64_6
