在mysqld.log我有数千行，如：
Table mysql/innodb_index_stats has length mismatch in the column name table_name. Please run mysql_upgrade
因此，根据几乎所有关于此事的帖子（以及错误消息本身）：
mysql_upgrade -u root -p
Enter password:
Checking if update is needed.
Checking server version.
Running queries to upgrade MySQL server.
Checking system database.
...
并且所有数据库中的所有表都像
...
mysql.columns_priv OK
mysql.db OK
mysql.engine_cost OK
mysql.event OK
mysql.func OK
mysql.general_log OK
mysql.gtid_executed OK
mysql.help_category OK
mysql.help_keyword OK
mysql.help_relation OK
mysql.help_topic OK
mysql.innodb_index_stats OK
mysql.innodb_table_stats OK
mysql.ndb_binlog_index OK
mysql.plugin OK
mysql.proc OK
mysql.procs_priv OK
mysql.proxies_priv OK
mysql.server_cost …