What the MySQL Upgrade Process Upgrades Note Because the server upgrades the Performance Schema,  INFORMATION_SCHEMA , and the objects described in step 2 as of MySQL 8.0.16,  mysql_upgrade  is unneeded and is deprecated as of that version; expect it to be removed in a future version of MySQL. Most aspects of what occurs during step 2 are the same prior to and as of MySQL 8.0.16, although different command options may be needed to achieve a particular effect. As of MySQL 8.0.16, the  --upgrade  server option controls whether and how the server performs an automatic upgrade at startup: •With no option or with  --upgrade=AUTO , the server upgrades anything it determines to be out of date (steps 1 and 2). •With  --upgrade=NONE , the server upgrades nothing (skips steps 1 and 2), but also exits with an error if the data dictionary must be upgraded. It is not possible to run the server with an out-of-date data dictionary; the server insists on either upgrading it or exiting. •With  --upgrade=MINIMAL , the server upgrades the data dictionary, the Performance Schema, and the INFORMATION_SCHEMA , if necessary (step 1). Note that following an upgrade with this option, Group Replication cannot be started, because system tables on which the replication internals depend are not updated, and reduced functionality might also be apparent in other areas. •With  --upgrade=FORCE , the server upgrades the data dictionary, the Performance Schema, and the INFORMATION_SCHEMA , if necessary (step 1), and forces an upgrade of everything else (step 2). Expect server startup to take longer with this option because the server checks all objects in all schemas. FORCE  is useful to force step 2 actions to be performed if the server thinks they are not necessary. One way that  FORCE  differs from  AUTO  is that with  FORCE , the server re-creates system tables such as help tables or time zone tables if they are missing. The following list shows upgrade commands prior to MySQL 8.0.16 and the equivalent commands for MySQL 8.0.16 and higher: •Perform a normal upgrade (steps 1 and 2 as necessary): •Perform only step 1 as necessary: •As of MySQL 8.0.16:  mysqld •Prior to MySQL 8.0.16:  mysqld  followed by  mysql_upgrade •Prior to MySQL 8.0.16: It is not possible to perform all upgrade tasks described in step 1 while excluding those described in step 2. However, you can avoid upgrading user schemas and the  sys schema using  mysqld  followed by  mysql_upgrade  with the  --upgrade-system-tables  and  -- skip-sys-schema  options. •As of MySQL 8.0.16:  mysqld --upgrade=MINIMAL •Perform step 1 as necessary, and force step 2: •Prior to MySQL 8.0.16:  mysqld  followed by  mysql_upgrade --force •As of MySQL 8.0.16:  mysqld --upgrade=FORCE Prior to MySQL 8.0.16, certain  mysql_upgrade  options affect the actions it performs. The following table shows which server  --upgrade  option values to use as of MySQL 8.0.16 to achieve similar effects. 265