I was wondering if, and how much, using tmpfs could improve MySQL performance and how it should be done ? My guess would be to do mount -t tmpfs -o size=256M /path/to/mysql/data/DatabaseName, and to use the database normally but maybe I'm wrong (I'm using MyISAM tables only).

Will a hourly rsync between the tmpfs /path/to/mysql/data/DatabaseName and /path/to/mysql/data/DatabaseName_backup penalize performances ? If so, how should I make the backup of the tmpfs database ?

So, is it a good way to do things, is there a better way or am I losing my time ?