2.11.2 Downgrading MySQL Downgrading to MySQL 5.1 Downgrading
from MySQL Enterprise Edition to MySQL Community Server  This
section describes what you should do to downgrade to an older
MySQL version in the unlikely case that the previous version
worked better than the new one.     The following items form a
checklist of things you should do whenever you perform a
downgrade:        2. Restart the newer MySQL server you are
downgrading from.     It might also be the case that system
tables in the mysql database have changed and that downgrading
introduces some loss of functionality or requires some
adjustments. Here are some examples: