I'm using an add-on that adds a "Most Followers" tab at the Notable Members list (I can't mention the author because he got recently banned here). Well the problem is that when viewing the "Most Followers" tab at the Notable Members list I have a slow query that uses around 85% of my CPU:
Isn't this due to a missing index? As far as I know when a query says "using filesort" it means that an index would be of help. For example take a look at the stock XF query that processes the "Most Messages" tab at the Notable Members list:
As you can see the stock XF query doesn't "uses filesort".
How I can improve the performance of the query being used on the "Most Followers" add-on? Maybe because XF itself doesn't include a "Most Followers" tab then it doesn't have the proper index to help that process?