Дмитрий Энтелис

select 	
    (
      select avg(Rating.stars)  
      from Movie 
      join Rating on Rating.mID = Movie.mID
      where year < 1980 
    ) - (
      select avg(Rating.stars)  
      from Movie 
      join Rating on Rating.mID = Movie.mID
      where year >= 1980 
    ) as diff;

getFile
Use this method to get basic info about a file and prepare it for downloading. For the moment, bots can download files of up to 20MB in size. On success, a File object is returned. The file can then be downloaded via the link https://api.telegram.org/file/bot%token%/%file_path%, where %file_path% is taken from the response. It is guaranteed that the link will be valid for at least 1 hour. When the link expires, a new one can be requested by calling getFile again.

Make InnoDB access all your cores
Increase innodb_buffer_pool_size to 12G
Increase innodb_buffer_pool_instances to 2 (First run numactl --hardware to determine the number of Physical CPUs. What every number of CPUs it reports, use that number. I learned this recently in Jeremy Cole's Blog)
Increase Log File Size (innodb_log_file_size) to 2047M
support separate tablespace files for individual InnoDB tables (enable innodb_file_per_table)
support either high performance or high durability (ACID Compliance)
Increase Size up the innodb_log_buffer_size in conjunction with the number of transactions per second (perhaps 32M)
Increase innodb_read_io_threads to 64
Increase innodb_write_io_threads to 64
Increase innodb_io_capactity to 10000