オリジナル版：http://dev.mysql.com/doc/refman/5.1/en/news-5-1-57.html
最も普及しているオープンソースデータベース管理システムの新バージョンMySQL Community Server 5.1.57がリリースされました。MySQL 5.1.57は、プロダクションシステムでの使用をお勧めします。
MySQL 5.1の新機能の概要については、以下を参照してください。
http://dev.mysql.com/doc/refman/5.1/en/mysql-nutshell.html
新たなサーバにMySQL 5.1.57をインストール、または以前のMySQLリリースからMySQL 5.1.57にアップグレードする際の情報については、以下を参照してください。
http://dev.mysql.com/doc/refman/5.1/en/installing.html
下記のダウンロードページから、MySQLサーバのソースコード及び多数のプラットフォーム用バイナリが入手可能です
http://dev.mysql.com/downloads/
現時点ですべてのミラーサイトが最新であるとは限らないことに注意してください。
あるミラーサイトで本バージョンを見つけることができない場合は、後日再確認を行うか、別のダウンロード・サイトを選択してください。
フィードバック、バグレポート、バグ修正、パッチ等の情報をお待ちしておりますので、以下のページをご利用ください。
http://forge.mysql.com/wiki/Contributing
MySQL 5.1に関するオープンな問題の情報については、以下のエラッタリストを参照してください。
http://dev.mysql.com/doc/refman/5.1/en/open-bugs.html
以下のセクションは、MySQL5.1の前リリース以降のMySQLソースコードの変更を記載しています。これはオンラインでも閲覧可能です：
http://dev.mysql.com/doc/refman/5.1/en/news-5-1-57.html
以下は、追加または変更された機能です。
Changes in MySQL 5.1.57 (May 05, 2011)
Functionality added or changed:
* When invoked with the --auto-generate-sql option, mysqlslap
dropped the schema specified with the --create-schema option
at the end of the test run, which may have been unexpected by
the user. mysqlslap no longer drops the schema, but has a new
--create-and-drop schema that both creates and drops a schema.
(Bug #58090, Bug #11765157)
* A new system variable, max_long_data_size, now controls the
maximum size of parameter values that can be sent with the
mysql_stmt_send_long_data() C API function. If not set at
server startup, the default is the value of the
max_allowed_packet system variable. This variable is
deprecated. In MySQL 5.6, it is removed and the maximum
parameter size is controlled by max_allowed_packet.
Bugs fixed:
* InnoDB Storage Engine: Replication: Trying to update a column,
previously set to NULL, of an InnoDB table with no primary key
caused replication to fail with Can't find record in 'table'
on the slave. (Bug #11766865, Bug #60091)
* InnoDB Storage Engine: The server could halt if InnoDB
interpreted a very heavy I/O load for 15 minutes or more as an
indication that the server was hung. This change fixes the
logic that measures how long InnoDB threads were waiting,
which formerly could produce false positives. (Bug #11877216,
Bug #11755413, Bug #47183)
* Replication: Using the --server-id option with mysqlbinlog
could cause format description log events to be filtered out
of the binary log, leaving mysqlbinlog unable to read the
remainder of the log. Now such events are always read without
regard to the value of this option.
As part of the fix for this problem, mysqlbinlog now also
reads rotate log events without regard to the value of
--server-id. (Bug #11766427, Bug #59530)
* Partitioning: A problem with a previous fix for poor
performance of INSERT ON DUPLICATE KEY UPDATE statements on
tables having many partitions caused the handler function for
reading a row from a specific index to fail to store the ID of
the partition last used. This caused some statements to fail
with Can't find record errors. (Bug #59297, Bug #11766232)
* InnoDB invoked some zlib functions without proper
initialization. (Bug #11849231)
* Selecting from a view for which the definition included a
HAVING clause failed with an error:
1356: View '...' references invalid table(s) or column(s)
or function(s) or definer/invoker of view lack rights to use them
(Bug #60295, Bug #11829681)
* The server permitted max_allowed_packet to be set lower than
net_buffer_length, which does not make sense because
max_allowed_packet is the upper limit on net_buffer_length
values. Now a warning occurs and the value remains unchanged.
(Bug #59959, Bug #11766769)
* The server read one byte too many when trying to process an
XML string lacking a closing quote (') or double quote (")
character used as an argument for UpdateXML() or
ExtractValue(). (Bug #59901, Bug #11766725)
See also Bug #44332, Bug #11752979.
* Attempting to create a spatial index on a CHAR column longer
than 31 bytes led to an assertion failure if the server was
compiled with safemutex support. (Bug #59888, Bug #11766714)
* Aggregation followed by a subquery could produce an incorrect
result. (Bug #59839, Bug #11766675)
* An incorrect character set pointer passed to
my_strtoll10_mb2() caused an assertion to be raised. (Bug
#59648, Bug #11766519)
* A missing variable initialization for Item_func_set_user_var
objects could cause an assertion to be raised. (Bug #59527,
Bug #11766424)
* mysqldump did not quote database names in ALTER DATABASE
statements in its output, which could cause an error at reload
time for database names containing a dash. (Bug #59398, Bug
#11766310)
* In Item_func_month::val_str(), a Valgrind warning for a
too-late NULL value check was corrected. (Bug #59166, Bug
#11766126)
* In Item::get_date, a Valgrind warning for a missing NULL value
check was corrected. (Bug #59164, Bug #11766124)
* In extract_date_time(), a Valgrind warning for a missing
end-of-string check was corrected. (Bug #59151, Bug #11766112)
* In string context, the MIN() and MAX() functions did not take
into account the unsignedness of a BIGINT UNSIGNED argument.
(Bug #59132, Bug #11766094)
* In Item_func::val_decimal, a Valgrind warning for a missing
NULL value check was corrected. (Bug #59125, Bug #11766087)
* In Item_func_str_to_date::val_str, a Valgrind warning for an
uninitialized variable was corrected. (Bug #58154, Bug
#11765216)
* The code for PROCEDURE ANALYSE() had a missing DBUG_RETURN
statement, which could cause a server crash in debug builds.
(Bug #58140, Bug #11765202)
* An assertion could be raised in
Item_func_int_val::fix_num_length_and_dec() due to overflow
for geometry functions. (Bug #57900, Bug #11764994)
* An assertion could be raised if a statement that required a
name lock on a table (for example, DROP TRIGGER) executed
concurrently with an INFORMATION_SCHEMA query that also used
the table. (Bug #56541, Bug #11763784)
* For a client connected using SSL, the Ssl_cipher_list status
variable was empty and did not show the possible cipher types.
(Bug #52596, Bug #11760210)
* With lower_case_table_names=2, resolution of objects qualified
by database names could fail. (Bug #50924, Bug #11758687)
* A potential invalid memory access discovered by Valgrind was
fixed. (Bug #48053, Bug #11756169)
* Bitmap functions used in one thread could change bitmaps used
by other threads, causing an assertion to be raised. (Bug
#43152, Bug #11752069)
* SHOW EVENTS did not always show events from the correct
database. (Bug #41907, Bug #11751148)