How grab one post ?

[roxxx]

ok,

so I have:

<?
require("global.php");
$res = mysql_query("SELECT * FROM post WHERE postid='1111'");
 $row= (mysql_fetch_row($res));
echo ($row[7]);
?>

and it's display this post in other site, but when I want to add new plugin file .php with this code,
forum display error:

Fatal error: Allowed memory size of 16777216 bytes exhausted (tried to allocate 311296 bytes) in ............. global.php on line 472

I have limit memory in php.ini 16M.

Is it problem this code or limit ?