MySQL Server memory Usage Summary

The amount of memory used by the active link (dynamic) is as follows:

Per_connection_memory =//memory for sequential table scans//  memory for Buffering reads//  memory ofr in mem sorts//per connection memory// memory for in mem table joins

The amount of memory used per server (fixed) is as follows:

Per_server_memory =//memory for all temp tables//  max size of single temp table
    //Memory allocated for index blocks//  main cache for InnoDB data//  InnoDB record Structure Cache//  log file Write buffer//  compiled statement Cache

The maximum memory that MySQL can use is defined as follows:

Max_memory = (per_connection_memory* max _connections) + per_server_memory

MySQL Server memory Usage Summary