I'm working on a development in WordPress/WooCommerce which has a very large number of products, currently 180,000. The problem here is, of MySQL which slows down dramatically as the product number exceeds 60,000. This is mainly due to MySQL apparently using the Ubuntu filing system to store data. It would be better if a different database could be used but in the meantime I was considering setting up a RAMdisk and using that for the MySQL temp data. Now there are any number of posts on how to do it, all of which are wrong for Ubuntu 20.04. Running 'df' I can see a mount point at /dev/shm which appears to be usable and wondered if it is. My knowledge of Linux isn't great enough to be sure. Tutorials also suggest editing /etc/rc.local which no longer exists in Ubunto 20 along with /etc/apparmor.d/local/usr.sbin.mysqld which also doesn't exist. Also /etc/mysql/my.cnf has no reference to tmpdir. All this would appear to indicate that what I'd like to do (other than use a grown up database like PostgreSQL or SQL-Server) can't be done or perhaps doesn't need to be done. Of course running the whole MySQL database in RAM would be fast but unfeasible, I know.