Converting AWS RDS Databases to InnoDB, does database "mysql" need to be converted?

3
votes

I am converting all RDS databases to InnoDB for obvious reasons. However I am still getting notifications that not all my databases are using InnoDB. The only tables that are not InnoDB belong to information_schema and the schema named "mysql". I'm not converting these tables because I am afraid it would break the database.

Do not convert MySQL system tables in the mysql database (such as user or host) to the InnoDB type. This is an unsupported operation. The system tables must always be of the MyISAM type.

Can I convert the database named mysql? This is the message I'm getting from AWS.

This DB Instance also contains MyISAM tables that have not been migrated to InnoDB. These tables can impact your ability to perform point-in-time restores. Consider converting these tables to InnoDB.

1
mysqlinnodbmyisamrds
The AWS message is wrong. Almost all tables in database mysql must be MyISAM. – akuzminsky
Agree with @akuzminsky, do not modify the tables in the mysql schema. But do verify that SELECT * FROM information_schema.tables WHERE ENGINE='MyISAM' AND table_schema != 'mysql'; does not return any tables you have overlooked. – Michael - sqlbot
Yes I've already verified that there is nothing overlooked. I also restarted the database. I'll create an AWS ticket. – Neo

1 Answers

2
votes

Do not touch tables in databases mysql, performance_schema, sys, or sys_schema (if they exist).

Some subtle issues in the engine conversion are listed here: http://mysql.rjweb.org/doc.php/myisam2innodb