In our last customer project we had around 600 Gbyte of data in a MySQL database. Because this database consumed a significant amount of our disk space and backups with the InnoDB backup tool took pretty long we wanted to find out if we could get rid of some of the tables.
This application was growing over the last 10 years and it was not clear if some tables are still in use or not.
But how to find out when a table was touched last? MySQL/InnoDB theoretically could know about but does not report this information.