Code: MySQL started within last 24 hours - recommendations may be inaccurate Reduce your SELECT DISTINCT queries which have no LIMIT clause Performance should be activated for better diagnostics Consider installing Sys schema from https://github.com/mysql/mysql-sys Variables to adjust: query_cache_size (=0) query_cache_type (=0) query_cache_limit (> 1M, or use smaller result sets) tmp_table_size (> 16M) max_heap_table_size (> 16M) performance_schema = ON enable PFS innodb_buffer_pool_size (>= 4G) if possible. innodb_log_file_size should be (=16M) if possible, so InnoDB total log files size equals to 25% of buffer pool size. Got the above results. How can I activate performance? Is it totally safe to install mysql-sys? Will that allow mysqltuner to access to more db usage details? mysql service is running more than 24 hours ago if I'm not wrong. Am I missing something? Is it enough to run it through perl like How to Optimize MySQL Performance Using MySQLTuner instructions?