Failure to follow the downgrading procedure described in Section 11.3, “How to Downgrade” may lead to compatibility issues when files written by the InnoDB storage engine are accessed by the built-in InnoDB in MySQL. This section describes some internal recovery algorithms, to help explain why it is important to follow the downgrade procedure described above. It discusses the issues that may arise, and covers possible ways to fix them.

A general fix is to install the plugin as described in Chapter 9, Installing the InnoDB Storage Engine and then follow the downgrading procedure described in Section 11.3, “How to Downgrade”.

In the future, the file format management features described in Chapter 4, InnoDB File Format Management will guard against the types of problems described in this section.