Xdebug's built-in profiler allows you to find bottlenecks in your script and visualize those with an external tool such as KCacheGrind or WinCacheGrind
SELECT tag,bCount FROM sc_hottags ORDER BY RAND(),bCount DESC, tag
LIMIT 25 in /home/usebetac/public_html/marktag.com/includes/db/mysql.php on line 390