Server System Variables considered unequal, and each  NULL  forms a distinct value group of size 1. For  nulls_ignored ,  NULL values are ignored. The method that is used for generating table statistics influences how the optimizer chooses indexes for query execution, as described in Section 8.3.8, “InnoDB and MyISAM Index Statistics Collection” . Use memory mapping for reading and writing  MyISAM  tables. This variable controls whether the  mysql_native_password  built-in authentication plugin supports proxy users. It has no effect unless the  check_proxy_users  system variable is enabled. For information about user proxying, see Section 6.2.18, “Proxy Users” . (Windows only.) Indicates whether the server supports connections over named pipes. 842 • named_pipe • mysql_native_password_proxy_users • myisam_use_mmap Command-Line Format --myisam-use-mmap[={OFF|ON}] System Variable myisam_use_mmap Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Boolean Default Value OFF Command-Line Format --mysql-native-password-proxy- users[={OFF|ON}] System Variable mysql_native_password_proxy_users Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Boolean Default Value OFF Command-Line Format --named-pipe[={OFF|ON}] System Variable named_pipe Scope Global Dynamic No SET_VAR  Hint Applies No Platform Specific Windows Type Boolean Default Value OFF