for queries acquiring locks, blocking other queries, or for extremely long queries which are wasting system resources.
A good heuristic would be to look for queries running the longest.
</p>
<p>
However, PROCESSLIST also lists down many other connections, including those sleeping for long time. 
<i>processlist_top</i> provides with the short story: only active, and longest first. 
This is similar to query listing as implemented in <a href="http://jeremy.zawodny.com/mysql/mytop/">mytop</a> 
or <a href="http: