Медленные запросы к базе

public function query($sql, $ignore_errors=false){
 
    $inConf = cmsConfig::getInstance();
 
        $sql = $this->replacePrefix($sql);
 
if ($inConf->debug){
 
        $mtime = microtime();
 
        $mtime = explode(" ",$mtime);
 
        $mtime = $mtime[1] + $mtime[0];
 
        $tstart = $mtime;
 
                   }
 
    $result = mysql_query($sql, $this->db_link);
 
if ($inConf->debug){
 
        $mtime = microtime();
 
        $mtime = explode(" ",$mtime);
 
        $mtime = $mtime[1] + $mtime[0];
 
        $tend = $mtime;
 
        $tpassed = ($tend - $tstart);
 
                   }
 
    if ($inConf->debug){
 
        $this->q_count  += 1;
 
        $this->q_dump   .= '<pre>'.$sql.' <b style="color:'.($tpassed<0.1 ? 'green' : 'red').';">'.$tpassed.' сек.</b></pre><hr/>';
 
    }
 
 
 
    if (mysql_error() && $inConf->debug && !$ignore_errors){
 
        die('<div style="margin:2px;border:solid 1px gray;padding:10px">DATABASE ERROR: <pre>'.$sql.'</pre>'.mysql_error().'</div>');
 
    }
 
 
 
    return $result;
 
}

 
 
SELECT p.pubdate, p.id AS post_id,
				   u.id AS uid, u.nickname AS author,
                   u.login AS author_login, 
				   t.title AS threadtitle, t.id AS threadid
			FROM cms_forum_posts p
			LEFT JOIN cms_forum_threads t ON t.id = p.thread_id AND t.is_hidden=0
			INNER JOIN cms_forums f ON f.id = t.forum_id
			LEFT JOIN cms_users u ON u.id = p.user_id
			WHERE (f.NSLeft >= 94 AND f.NSRight <= 95)
			ORDER BY p.id DESC
			LIMIT 1 
 
 

 
 
SELECT p.id
				FROM cms_forum_posts p
				INNER JOIN cms_forum_threads t ON t.id = p.thread_id
				INNER JOIN cms_forums f ON f.id = t.forum_id AND f.NSLeft >= '94' AND f.NSRight <= '95' AND f.published = 1 
 
 

SELECT `user_names`.`name` FROM ..