SELECT * FROM
                    (
                    SELECT p.post_id, p.post_message, UNIX_TIMESTAMP(p.date_posted) as date_posted, u.username FROM posts p
                    INNER JOIN friend_match fm
                        ON p.poster_id = fm.friend1
                    INNER JOIN user_info u
                        ON u.account_id = p.poster_id
                    WHERE fm.friend2 = $sessionid

UNION ALL

                    SELECT p.post_id, p.post_message, UNIX_TIMESTAMP(p.date_posted) as date_posted, u.username FROM posts p
                    INNER JOIN user_info u
                        ON u.account_id = p.poster_id
                    WHERE p.poster_id = $sessionid
                    )z
                    ORDER BY post_id DESC LIMIT $page,$limit";

SELECT * FROM posts p
  inner join user_info u ON u.account_id = p.poster_id
WHERE p.poster_id = $sessionid or p.poster_id IN
(SELECT f.friend1 FROM friend_match f
 WHERE f.friend2 = $sessionid)
ORDER BY post_id DESC LIMIT $page, $limit;