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