Functionality added or changed:
CHARACTER SET xxx and CHARSET=xxx
table options (to be able to read table dumps from 4.1).
IFNULL(A,B) is now set to be the
more 'general' of the types of A and B. (The order is
STRING, REAL or INTEGER).
mysql.server startup script in the RPM packages from
`/etc/rc.d/init.d/mysql' to `/etc/init.d/mysql'
(which almost all current Linux distributions support for LSB compliance).
Qcache_lowmem_prunes status variable (number of queries that were
deleted from cache because of low memory).
mysqlcheck so it can deal with table names containing dashes.
SHOW VARIABLES)
is no longer used when inserting small (less than 100) number of rows.
SELECT ... FROM merge_table WHERE indexed_column=constant_expr.
LOCALTIME and LOCALTIMESTAMP as synonyms for
NOW().
CEIL is now an alias for CEILING.
CURRENT_USER() function can be used to get a user@host
value as it was matched in the GRANT system.
See section 6.3.6.2 Miscellaneous Functions.
CHECK constraints to be compatible with SQL-99. This made
CHECK a reserved word. (Checking of CHECK constraints is
still not implemented).
CAST(... as CHAR).
LIMIT syntax:
SELECT ... LIMIT row_count OFFSET offset
mysql_change_user() will now reset the connection to the state
of a fresh connect (Ie, ROLLBACK any active transaction, close
all temporary tables, reset all user variables etc..)
Bugs fixed:
multi table updates
--lower-case-table-names default on Mac OS X as the default
file system (HFS+) is case insensitive.
See section 6.1.3 Case Sensitivity in Names.
AUTOCOMMIT=0 mode didn't rotate binary log.
SELECT with joined tables with
ORDER BY and LIMIT clause when filesort had to be used.
In that case LIMIT was applied to filesort of one of the tables,
although it could not be.
This fix solved problems with LEFT JOIN too.
mysql_server_init() now makes a copy of all arguments. This fixes
a problem when using the embedded server in C# program.
libmysqlclient library
that allowed a malicious MySQL server to crash the client
application.
mysql_change_user() handling.
All users are strongly recommended to upgrade to version 4.0.6.
--chroot command-line option of
mysqld from working.
"..." in boolean full-text search.
OPTIMIZE TABLE to corrupt the table
under some rare circumstances.
LOCK TABLES now works together with multi-table-update and
multi-table-delete.
--replicate-do=xxx didn't work for UPDATE commands.
(Bug introduced in 4.0.0)
InnoDB bugs in REPLACE, AUTO_INCREMENT,
INSERT INTO ... SELECT ... were fixed. See the InnoDB changelog
in the InnoDB section of the manual.