La close Limit avec oracle

<?php
$c = oci_connect("hr", "hrpwd", "localhost/XE");
$mystmt = "select city from locations order by city";
$minrow = 4; // row number of first row to return
$maxrow = 8; // row number of last row to return
$pagesql = "select *
from ( select a.*, rownum as rnum
from ( $mystmt ) a
where rownum <= :maxrow)
where rnum >= :minrow";
$s = oci_parse($c, $pagesql);
oci_bind_by_name($s, ":maxrow", $maxrow);
oci_bind_by_name($s, ":minrow", $minrow);
oci_execute($s);
oci_fetch_all($s, $res);
var_dump($res);
?>