optimum mysql configuration

 [mysql]  
 # CLIENT #  
 port              = 3306  
 socket             = /var/lib/mysql/mysql.sock  
 [mysqld]  
 # GENERAL #  
 user              = mysql  
 default-storage-engine     = InnoDB  
 socket             = /var/lib/mysql/mysql.sock  
 pid-file            = /var/lib/mysql/mysql.pid  
 # MyISAM #  
 key-buffer-size        = 32M  
 myisam-recover         = FORCE,BACKUP  
 # SAFETY #  
 max-allowed-packet       = 16M  
 max-connect-errors       = 1000000  
 sort_buffer_size = 1073741824  
 myisam_sort_buffer_size = 1073741824  
 # DATA STORAGE #  
 datadir            = /var/lib/mysql/  
 # BINARY LOGGING #  
 #log-bin            = /var/lib/mysql/mysql-bin  
 #expire-logs-days        = 14  
 #sync-binlog          = 1  
 # CACHES AND LIMITS #  
 #tmp-table-size         = 32M  
 #max-heap-table-size      = 32M  
 tmp-table-size         = 1G  
 max-heap-table-size      = 1G  
 query-cache-type        = 0  
 query-cache-size        = 0  
 max-connections        = 500  
 thread-cache-size       = 50  
 open-files-limit        = 65535  
 table-definition-cache     = 4096  
 table-open-cache        = 4096  
 join_buffer_size = 1048576  
 # INNODB #  
 innodb-flush-method      = O_DIRECT  
 innodb-log-files-in-group   = 2  
 innodb-log-file-size      = 256M  
 innodb-flush-log-at-trx-commit = 1  
 innodb-file-per-table     = 1  
 innodb-buffer-pool-size    = 12G  
 # LOGGING #  
 log-error           = /var/lib/mysql/mysql-error.log  
 log-queries-not-using-indexes = 1  
 slow-query-log         = 1  
 slow-query-log-file      = /var/lib/mysql/mysql-slow.log