MySQL query caching: limited to a maximum cache size of 128 MB?

Question

My application is very database intensive so I\'ve tried really hard to make sure the application and the MySQL database are working as efficiently as possible together.

Answer 1

Overhead for Query cache is around 10% so I would disable query caching. Usually if you can't get your hit rate over 40 or 50 % maybe query cache isn't right for your database.

I've blog about this topic... Mysql query_cache_size performance here.