I hope my question won't be closed for being vague, but the system I'm working with has a 455MB ci_sessions table with 150MB of overhead and I feel like the site is sluggish.
I think it could be in part because of that table that I think has lots of writing to it. It is currently using MYIsam engine. Would it be better to use InnoDB?
Also, would it be a good idea to set a cronjob to do OPTIMIZE TABLE ci_session
? Would a smaller overhead speed up the website? And would it only last 5 minutes before the overhead is back to 150MB (I don't want to hit the optimize query before having an external opinion)?