问题
I've installed MySQL 5.5 recently. I'm using InnoDB as the engine for all my databases. I noticed that the mysql database default and all of it's tables (user, db, etc...) are MyISAM. Is there any reason they cannot / should not be InnoDB? Does anyone know if MySQL requires the mysql db to be MyISAM?
回答1:
Warning Do not convert MySQL system tables in the mysql database from MyISAM to InnoDB tables! This is an unsupported operation. If you do this, MySQL does not restart until you restore the old system tables from a backup or re-generate them with the mysql_install_db script.
http://dev.mysql.com/doc/refman/5.0/en/innodb-restrictions.html
来源：https://stackoverflow.com/questions/12902829/can-the-mysql-system-database-tables-be-converted-to-innodb