mysqld as root, you must now use the --user=root option.
FLUSH TABLES command.
slow_launch_time variable and the Slow_launch_threads
status variable to mysqld. These can be examined with
mysqladmin variables and mysqladmin extended-status.
INET_NTOA() and INET_ATON().
IF() now depends on the second and
third arguments and not only on the second argument.
myisamchk could go into a loop when trying to
repair a crashed table.
INSERT DELAYED to update log if SQL_LOG_UPDATE=0.
REPLACE on HEAP tables.
SHOW VARIABLES output.
DELETE of many rows on a table with
compressed keys where MySQL scanned the index to find the rows.
CHECK on table with deleted keyblocks.
LAST_INSERT_ID() to update
a table with an AUTO_INCREMENT key.
NULLIF() function.
LOAD DATA INFILE on a table with
BLOB/TEXT columns.
MyISAM to be faster when inserting keys in sorted order.
EXPLAIN SELECT ... now also prints out whether MySQL needs to
create a temporary table or use file sorting when resolving the SELECT.
ORDER BY parts where the part is a
constant expression in the WHERE part. Indexes can now be used
even if the ORDER BY doesn't match the index exactly, as long as
all the unused index parts and all the extra ORDER BY
columns are constants in the WHERE clause. See section 5.4.3 How MySQL Uses Indexes.
UPDATE and DELETE on a whole unique key in the WHERE part
are now faster than before.
RAID_CHUNKSIZE to be in 1024-byte increments.
LOAD_FILE(NULL).