Thanks RHD. I thought as much. It's the UserIndexStat and UserTableStat tables. They have a field on them called xxx-conn which is a foreign key to the _connect table. If I want to find out what tables and indexes a specific user is hammering the query is pretty slow, and if I want to break it down for all users every five minutes, say, the query doesn't complete before the next iteration is needed. You can fudge it but it's not 100% accurate, particularly if the same user is logged in many times.