本家の ML にリリース情報が流れてない（と思う…）ので気が付かなかったん
ですが、いつの間にか MySQL-3.21.31 と 3.22.1-alpha というのが出てました。

変更点をドキュメントから引用します。

3.22 でかなり変わったようですが、私が気になった点をいくつかピックアップ
してみます。

・異なるデータベース間のテーブルを同時に扱えるようになった。
・一般ユーザがパスワードを簡単に変更できるようになった。
・x86 Linux ではいくつかの文字列関数がアセンブラで書かれて高速になった。
・テーブルに項目を追加する時に、項目の位置を指定できるようになった。

--
民斗 <tommy@xxxxxxxxxx>


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Changes in release 3.21.31
--------------------------

   * Fixed a sign extension problem for the type 'tiny' on IRIX.

   * Fixed problem with left("constant_string",function).

   * Fixed problem with find_in_set().

   * LEFT JOIN core dumped if the second table is used with a constant
     WHERE/ON expression with uniquely identifies one record.

   * Fixed problems with date_format() and wrong dates.  date_format()
     now ignores '%' to make it possible to extend it more easily in
     the future.

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Changes in release 3.22.0
-------------------------

   * New (backward compatible) connect protocol that allows one to
     specify the database to use when connecting to get much faster
     onnections to a specific database.

            mysql_real_connect() call is changed to:
          
            mysql_real_connect(MYSQL *mysql,const char *host, const char *user,
                             const char *passwd, const char *db,
                             uint port, const char *unix_socket,uint client_flag
)

   * Each connection is handled by it's own thread, instead by the
     master accept() thread.  This fixes permanently the telnet bug
     that was a topic on the mail list some time ago.

   * All TCP/IP connections are now checked with backward resolving of
     the hostname to get better security. mysqld has now a local
     hostname resolve cache so connections should actually be faster
     than before even with this feature.

   * A site will automaticly be blocked from future connections if one
     repeatedly connects with a 'improper header' (like when one uses
     telnet)

   * One can now reference to tables in different databases with:
     table@database or database.table.  This makes it possible to give
     a users read access to some tables and write access to others by
     simple keeping them in different databases!

   * If mysqld is started as root, it can now change to be run as
     another user with the new -user option.

   * Added cacheing of users & access rights (for faster access rights
     checking)

   * Normal users (not anonymous ones) can change ones password with
     mysqladmin password 'new_password'.  This uses crypted passwords
     that are not logged in the normal mysql log!

   * All important string functions are now coded in assembler for x86
     Linux machines.  This gives a speedup of 10% in many cases.

   * For tables that have many columns the column names are now hashed
     for much faster column name lookup (this will speed up some
     benchmark tests a lot!)

   * Some benchmarks are changed for get better individual timing.
     (Some loops was so short that a specific test took < 2 seconds. The
     loops has been changed to take about 20 seconds to make it easier
     to compare different databases. 1 <-> 2  before is now 11 <-> 24
     which is much better)

   * Re-arranged select code to handle some very specific queries
     involving group functions (like COUNT(*)) without a GROUP BY but
     with HAVING. The following now works.

     SELECT count(*) as C from TABLE HAVING C > 1

   * Changed the protocol for field functions to be faster and avoid
     some mallocs().

   * Added flag -T32 to mysqld for running all queries under the main
     thread.  This makes it possible to debug mysqld under Linux with
     gdb!

   * Added optimization of 'not_null_column IS NULL' (needed for some
     Access queries)

   * Allow one to use STRAIGHT_JOIN between two tables to force the
     optimizer to join them in a specific order.

   * String functions now return VARCHAR() instead of CHAR() and the
     column type is now VARCHAR() for fields saved as VARCHAR().  This
     should make the MyODBC driver better, but may break some old MySQL
     clients that doesn't handle FIELD_TYPE_VARCHAR identical as
     FIELD_TYPE_CHAR.

   * CREATE INDEX and DROP INDEX are now implemented trough ALTER TABLE.
     CREATE TABLE is still the recommended (fast) way to create indexes.

   * Added option wait_timeout to mysqld.

   * Added time column to 'mysqladmin processes' to show how long a
     query has taken or how long a thread has sleeped.

   * Lots of new varibles to 'show variables' and some new to 'show
     status'

   * Added new type: YEAR. YEAR is stored on 1 byte with range 0,
     1901-2155.

   * Added new DATE type that is stored on 3 bytes instead of 4. All new
     tables will created with the new date type if one doesn't use
     -old-protocol.

   * Fixed bug in record caches;  One could get 'Error from table
     handler: #' on some OS from some queries.

   * New configure option for x86 machines (tested on Linux + gcc):
     -enable-assembler.  This will enable assembler functions for the
     most important string functions for more speed!

Changes in release 3.22.1
-------------------------

   * Added new C-API function: mysql_ping().

   * Added new API functions: mysql_init() and mysql_options().  One
     MUST now call mysql_init() before one calls mysql_real_connect().
     One doesn't have to call mysql_init() if one only uses
     mysql_connect().

   * Added mysql_option(..,MYSQL_OPT_CONNECT_TIMEOUT) so one can set a
     timeout for connecting to a server.

   * Added -timeout argument to mysqladmin (as a test of
     mysql_options()).

   * Added options AFTER column and FIRST to ALTER TABLE ... ADD
     columns.  This makes is possible to add a new column at some
     specific location in an old table.

   * WEEK() now takes an optional argument to allow handling of weeks
     when week starts on Monday (Some European countries), or Sunday.
     The default WEEK() assumes week start on Sunday().

   * TIME columns wasn't stored properly (bug in MySQL 3.22.0).

   * UPDATE now returns a update information about how many rows was
     matched, updated and if one got any 'warnings' when doing the
     update.

   * Fixed wrong result from 'format(-100,2)'.

   * enum() and set() columns was compared binary; Changed to be case
     insensitive.