SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function substring (children 1)
     ExpressionList (children 3)
      Function materialize (children 1)
       ExpressionList (children 1)
        Function CAST (children 1)
         ExpressionList (children 2)
          Literal \'abcdefgh\'
          Literal \'FixedString(8)\'
      Literal Int64_-2
      Literal Int64_-2
