Hi Russell So through either the slow query log, or catching it via SHOW FULL PROCESSLIST, or for a more extreme solution enabling the general query log (you can set it up with the path, but only enable it for a bit and then turn it off again - it would create a lot of stuffs), catch the actual query. Then run it with EXPLAIN <query> Post that the output from that here. Also it might be good to paste your SHOW TABLE STATUS for those tables here, I might be able to see more from that. And perhaps SHOW CREATE TABLE <tblname> \G from the mysql cmdline client for the table structure of each of these tables. At this point I wouldn't fuss with switching from MySQL to MariaDB, MySQL does a fine job generally. MySQL 5.6 is EOL now though, so something a bit newer might be good. Regards, Arjen.