ポピュラーなオープンソースデータベースの5.1"リリース候補"バージョンである、MySQL Server 5.1.22-rcリリースを誇りに思います。
これがまだ「候補」であることに留意し、そしてどのプレリリース版と同様に、製品レベルにシステムやクリティカルなデータを持つシステムに使用する際には注意してください。MySQL5.0を使用した製品レベルのシステムであれば、次のMySQL Enterpriseの製品説明に注目してください。
http://mysql.com/products/enterprise/
MySQL 5.1.22-rcリリースは、ダウンロードサイト（http://dev.mysql.com/downloads/）とミラーサイトで、ソースとバイナリ形式が入手可能です。全てのミラーサイトが現在最新版でないことに注意してください。もし、ミラーサイトにてこのバージョンが見当たらない場合は、後ほど再度ダウンロードを試みるか、他のダウンロードサイトを選択してください。
また、いくつかのミラーサイトでは破損したファイルが提供されている可能性があることに注意してください。私たちはミラーサイトの管理者とこの問題の解決に努力しています。
私たちは、あなたのフィードバック、バグレポート、バグフィックス、パッチなどを歓迎し評価します。
http://forge.mysql.com/wiki/Contributing
次のセクションは、最も最近にリリースされたMySQL5.1であるMySQL5.1.21-betaから、ソースコードが変更されたリストになります。オンラインでも確認できます。
http://dev.mysql.com/doc/refman/5.1/en/news-5-1-22.html
Functionality added or changed:
* There is a new innodb_autoinc_lock_mode system variable to
configure the locking behavior that InnoDB uses for generating
auto-increment values. The default behavior now is slightly
different from before, which involves a minor incompatibility
for multiple-row inserts that specify an explicit value for
the auto-increment column in some but not all rows.
This can be used to improve scalability and performance, see
Section 13.5.6.3, "How AUTO_INCREMENT Handling Works in InnoDB.":
http://dev.mysql.com/doc/refman/5.1/en/innodb-auto-increment-handling.html
Bugs fixed:
* NDB Cluster: Backups of TIMESTAMP columns made with
ndb_restore on a MySQL Cluster using data nodes hosts of one
endian could not be used to restore the cluster's data to data
node hosts of the other endian.
(Bug#30134:http://bugs.mysql.com/30134)
* NDB Cluster (Replication): Multi-master replication setups did
not handle --log-slave-updates correctly.
(Bug#30017:http://bugs.mysql.com/30017)
* When sorting rows in an INNODB table using a primary key,
where the sort was on the the primary key column and the DESC
operator was applied, the rows would be incorrectly sorted if
you included a simple WHERE field = value clause in the query.
(Bug#31001:http://bugs.mysql.com/31001)
* Replication of InnoDB partitioned tables could lose updates
with row-based or mixed replication format.
(Bug#28430:http://bugs.mysql.com/28430)
* mysql_install_db could fail to find its message file.
(Bug#30678:http://bugs.mysql.com/30678)
* Non-range queries of the form SELECT ... FROM ... WHERE
keypart_1=const, ..., keypart_n=const ORDER BY ... FOR UPDATE
sometimes were unnecessarily blocked waiting for a lock if
another transaction was using SELECT ... FOR UPDATE on the
same table. (Bug#28570:http://bugs.mysql.com/28570)
* Under some circumstances, a UDF initialization function could
be passed incorrect argument lengths.
(Bug#29804:http://bugs.mysql.com/29804)
* CONNECTION_ID() always returned 0 for the embedded server
(libmysqld). (Bug#30389:http://bugs.mysql.com/30389)
* The mysql_list_fields() C API function incorrectly set
MYSQL_FIELD::decimals for some view columns.
(Bug#29306:http://bugs.mysql.com/29306)
* Read lock requests that were blocked by a pending write lock
request were not allowed to proceed if the statement
requesting the write lock was killed.
(Bug#21281:http://bugs.mysql.com/21281)
* Memory corruption occurred for some queries with a top-level
OR operation in the WHERE condition if they contained equality
predicates and other sargable predicates in disjunctive parts
of the condition. (Bug#30396:http://bugs.mysql.com/30396)
* The server created temporary tables for filesort operations in
the working directory, not in the directory specified by the
tmpdir system variable.
(Bug#30287:http://bugs.mysql.com/30287)
* Using KILL QUERY or KILL CONNECTION to kill a SELECT statement
caused a server crash if the query cache was enabled.
(Bug#30201:http://bugs.mysql.com/30201)
* Operations that used the time zone replicated the time zone
only for successful operations, but did not replicate the time
zone for errors that need to know it.
(Bug#29536:http://bugs.mysql.com/29536)
* mysqldump from the MySQL 5.1.21 distribution could not be used
to create a dump from a MySQL 5.1.20 or older server.
(Bug#30123:http://bugs.mysql.com/30123)
* When using a combination of HANDLER... READ and DELETE on a
table, MySQL continued to open new copies of the table every
time, leading to an exhaustion of file descriptors. This was
caused in MySQL 5.1.15 by a fix for
Bug#21587:http://bugs.mysql.com/21587; the current fix
consists of reverting the earlier fix.
(Bug#29474:http://bugs.mysql.com/29474)
* Tables using the InnoDB storage engine incremented
AUTO_INCREMENT values incorrectly with ON DUPLICATE KEY
UPDATE. (Bug#28781:http://bugs.mysql.com/28781)