If you’re running MySQL 8 or Percona 8, then you’ll probably see lots of guides online that reference some out of data configuration that really only deals with functions in MySQL 5 that have been deprecated in MySQL 8 and Percona 8

Query Cache

No longer used, and removed from MySQL 8 and Percona 8, alternative is ProxySQL as per the following Percona article https://www.percona.com/blog/2018/02/07/proxysql-query-cache/