mysql5.6，数据库自带performance_schema，占用内存400M。
my.cnf文档
performance_schema = OFF
innodb_buffer_pool_size = 8M innodb_additional_mem_pool_size = 1M innodb_log_buffer_size = 1M
引用：http://nosqldb.org/p/55ceaac5c3f8a8336f3bf727
原文：http://www.cnblogs.com/shuia/p/6370070.html