Searching on multiple constant keys that matched more than 30% of the rows didn't always use the best possible key.
New functions <<, >>, RPAD() and LPAD().
You can now save default options (like passwords) in a configuration file (my.cnf).
Lots of small changes to get ORDER BY to work when no records are found when using fields that are not in GROUP BY (MySQL extension).
Added --chroot option to mysqld, to start mysqld in a chroot environment (by Nikki Chumakov <nikkic@cityline.ru>).
Trailing spaces are now ignored when comparing case-sensitive strings; this should fix some problems with ODBC and flag 512!
Fixed a core dump bug in the range optimizer.
Added --one-thread option to mysqld, for debugging with LinuxThreads (or glibc). (This replaces the -T32 flag)
Added DROP TABLE IF EXISTS to prevent an error from occurring if the table doesn't exist.
IF and EXISTS are now reserved words (they would have to be sooner or later).
Added lots of new options to mysqldump.
Server error messages are now in mysqld_error.h.
The server/client protocol now supports compression.
All bug fixes from MySQL Version 3.21.32.