MySQL 5.7 Release Notes
InnoDB as the preferred
storage engine for typical database applications, from single-user
wikis and blogs running on a local system, to high-end
applications pushing the limits of performance. In MySQL
InnoDB is the default storage
engine for new tables.
InnoDB cannot be disabled. The
option is deprecated and has no effect, and its use results in a
warning. Expect it to be removed in a future MySQL release. This
also applies to its synonyms (
--disable-innodb, and so forth).