DATE_FORMAT().
NOT IN.
{fn now() }
DATE and TIME values with NULL.
FLOAT. Previously, the
values were converted to INT values before sorting.
key_column=constant.
DOUBLE values sorted on integer results instead.
mysql no longer requires a database argument.
HAVING should be. According to the SQL standards, it should
be after GROUP BY but before ORDER BY. MySQL Version 3.20
incorrectly had it last.
USE database to start using another database.
mysqld doesn't crash even if you haven't done a
ulimit -n 256 before starting mysqld.