I would suggest setting the ROW TYPE for ttrss_entries to COMPRESSED – it will take a while if you have a large table but as long as you are IOPS limited and not CPU limited you should see a performance gain. I run on Percona MySQL 5.7 with a bit over 1 million rows in that table and my setup is quite snappy – even if stuff isn’t in the buffer pool.
Thanks for the suggestion. I’ll keep it in mind. However, because it’s a RPi, I’m not 100% sure where the CPU limit lies. That is, if I were to make it compressed, I’m not sure if I’d hit the CPU limit soon instead.