Server System Variables Default Value BASEDIR/lib/plugin The path name of the plugin directory. If the plugin directory is writable by the server, it may be possible for a user to write executable code to a file in the directory using  SELECT ... INTO DUMPFILE . This can be prevented by making plugin_dir  read only to the server or by setting  secure_file_priv  to a directory where  SELECT writes can be made safely. • port • preload_buffer_size • print_identified_with_as_hex Command-Line Format --port=port_num System Variable port Scope Global Dynamic No SET_VAR  Hint Applies No Type Integer Default Value 3306 Minimum Value 0 Maximum Value 65535 The number of the port on which the server listens for TCP/IP connections. This variable can be set with the  --port  option. The size of the buffer that is allocated when preloading indexes. As of MySQL 8.0.26, setting the session value of this system variable is a restricted operation. The session user must have privileges sufficient to set restricted session variables. See Section 5.1.9.1, “System Variable Privileges” . Command-Line Format --preload-buffer-size=# System Variable preload_buffer_size Scope Global, Session Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 32768 Minimum Value 1024 Maximum Value 1073741824 Command-Line Format --print-identified-with-as-hex[={OFF| ON}] Introduced 8.0.17 System Variable print_identified_with_as_hex 859