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_6
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.one
   ExpressionList (children 1)
    Identifier x
