Vid Luther started the topic Performance issues with the wp_bp_activities table in the forum Creating & Extending 3 years, 10 months ago
We’re running into some performance issues with a couple of sites using BuddyPress 1.9.2 with WordPress 3.8.1 on our systems.
The problem query seems to be called from the wp-activity-classes.php. At first glance of just the query itself, it seems that the explicit SQL HINT in the query is the culprit. Here’s a gist explaining it..
@zippykid Not recently active