SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function materialize (alias x) (children 1)
     ExpressionList (children 1)
      Function toFixedString (children 1)
       ExpressionList (children 2)
        Literal \'\'
        Literal UInt64_1
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.one
   ExpressionList (children 1)
    Identifier x
