The mysql.usertable now has a password_expiredcolumn. Its default value is 'N', but
can be set to 'Y'with the new ALTER USER statement. After an account's password has been
expired, all operations performed in subsequent connections to the server using the account result
in an error until the user issues a SET PASSWORDstatement to establish a new account password.
For more information, see Section 13.7.1.1, “ALTER USERSyntax”, and Section 6.3.6, “Password
Expiration and Sandbox Mode”.