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_4
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.one
   ExpressionList (children 1)
    Identifier x
