MySQL expected memory allocation

MySQL expected memory allocation

SELECT ROUND((
@@GLOBAL.key_buffer_size                     
+ @@GLOBAL.query_cache_size 
+ @@GLOBAL.tmp_table_size 
+ @@GLOBAL.innodb_buffer_pool_size 
+ @@GLOBAL.innodb_log_buffer_size 
+ @@GLOBAL.max_connections
* ( 
  @@GLOBAL.sort_buffer_size
  + @@GLOBAL.read_buffer_size 
  + @@GLOBAL.read_rnd_buffer_size 
  + @@GLOBAL.join_buffer_size 
  + @@GLOBAL.thread_stack 
  + @@GLOBAL.binlog_cache_size
)) / 1024 / 1024, 1) `Total MB`;