Server System Variables •Multiple-line statements. •Comments from a  #  character to the end of the line. •Comments from a  --   sequence to the end of the line. •C-style comments from a  /*  sequence to the following  */  sequence, including over multiple lines. •Multiple-line string literals enclosed within either single quote ( ’ ) or double quote ( " ) characters. If the server is started with the  --initialize  or  --initialize-insecure  option, it operates in bootstap mode and some functionality is unavailable that limits the statements permitted in the file. These include statements that relate to account management (such as  CREATE USER  or  GRANT ), replication, and global transaction identifiers. See Section 17.1.3, “Replication with Global Transaction Identifiers” . As of MySQL 8.0.17, threads created during server startup are used for tasks such as creating the data dictionary, running upgrade procedures, and creating system tables. To ensure a stable and predictable environment, these threads are executed with the server built-in defaults for some system variables, such as  sql_mode ,  character_set_server ,  collation_server ,  completion_type , explicit_defaults_for_timestamp , and  default_table_encryption . These threads are also used to execute the statements in any file specified with  init_file  when starting the server, so such statements execute with the server’s built-in default values for those system variables. InnoDB  system variables are listed in Section 15.14, “InnoDB Startup Options and System Variables” . These variables control many aspects of storage, memory use, and I/O patterns for  InnoDB  tables, and are especially important now that  InnoDB  is the default storage engine. The value to be used by the following  INSERT  or  ALTER TABLE  statement when inserting an AUTO_INCREMENT  value. This is mainly used with the binary log. • innodb_ xxx • insert_id • interactive_timeout The number of seconds the server waits for activity on an interactive connection before closing it. An interactive client is defined as a client that uses the  CLIENT_INTERACTIVE  option to mysql_real_connect() . See also  wait_timeout . • internal_tmp_disk_storage_engine Command-Line Format --interactive-timeout=# System Variable interactive_timeout Scope Global, Session Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 28800 Minimum Value 1 810