オリジナル版：http://dev.mysql.com/doc/refman/5.1/en/news-5-1-66.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 5.1.66がリリースされました。MySQL 5.1.66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 5.1.66をインストール、または以前のMySQLリリースからMySQL 5.1.61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-5-1-65.html
以下は、追加または変更された機能です。
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A.1.1. Changes in MySQL 5.1.66 (September 29, 2012)
Bugs Fixed
* InnoDB: Certain information_schema tables originally
introduced in MySQL 5.6 are now also available in MySQL
5.5 and MySQL 5.1: INNODB_BUFFER_PAGE
(http://dev.mysql.com/doc/refman/5.5/en/innodb-buffer-pag
e-table.html), INNODB_BUFFER_PAGE_LRU
(http://dev.mysql.com/doc/refman/5.5/en/innodb-buffer-pag
e-lru-table.html), and INNODB_BUFFER_POOL_STATS
(http://dev.mysql.com/doc/refman/5.5/en/innodb-buffer-poo
l-stats-table.html). (Bug #13113026)
* InnoDB: When a SELECT ... FOR UPDATE, UPDATE, or other
SQL statement scanned rows in an InnoDB table using a <
or <= operator in a WHERE clause, the next row after the
affected range could also be locked. This issue could
cause a lock wait timeout for a row that was not expected
to be locked. The issue occurred under various isolation
levels, such as READ COMMITTED
(http://dev.mysql.com/doc/refman/5.1/en/set-transaction.h
tml#isolevel_read-committed) and REPEATABLE READ
(http://dev.mysql.com/doc/refman/5.1/en/set-transaction.h
tml#isolevel_repeatable-read). (Bug #11765218)
* Partitioning: The buffer for the row currently read from
each partition used for sorted reads was allocated on
open and freed only when the partitioning handler was
closed or destroyed. For SELECT statements on tables with
many partitions and large rows, this could cause the
server to use excessive amounts of memory.
This issue has been addressed by allocating buffers for
reads from partitioned tables only when they are needed
and freeing them immediately once they are no longer
needed. As part of this fix, memory is now allocated for
reading from rows only in partitions that have not been
pruned (see Partition Pruning
(http://dev.mysql.com/doc/refman/5.1/en/partitioning-prun
ing.html)). (Bug #13025132)
References: See also Bug #11764622, Bug #14537277.
* Replication: In master-master replication with
--log-slave-updates
(http://dev.mysql.com/doc/refman/5.1/en/replication-optio
ns-slave.html#option_mysqld_log-slave-updates) enabled,
setting a user variable and then performing inserts using
this variable caused the Exec_master_log_position column
in the output of SHOW SLAVE STATUS
(http://dev.mysql.com/doc/refman/5.1/en/show-slave-status
.html) not to be updated. (Bug #13596613)
* Small sort_buffer_size
(http://dev.mysql.com/doc/refman/5.1/en/server-system-var
iables.html#sysvar_sort_buffer_size) values could result
in a server crash. (Bug #14111180)
* The libmysqlclient_r client library exported symbols from
yaSSL that conflict with OpenSSL. If a program linked
against that library and libcurl, it could crash with a
segmentation fault. (Bug #14068244)
* The argument for LIMIT must be an integer, but if the
argument was given by a placeholder in a prepared
statement, the server did not reject noninteger values
such as '5'. (Bug #13868860)
* Access to INFORMATION_SCHEMA tables through a view could
leak memory. (Bug #13734987)
* A query for a FEDERATED
(http://dev.mysql.com/doc/refman/5.1/en/federated-storage
-engine.html) table could return incorrect results when
the underlying table had a compound index on two columns
and the query included an AND condition on the columns.
(Bug #12876932)
* The argument to the --ssl-key
(http://dev.mysql.com/doc/refman/5.1/en/ssl-options.html#
option_general_ssl-key) option was not verified to exist
and be a valid key. The resulting connection used SSL,
but the key was not used. (Bug #62743, Bug #13115401)
* In debug builds, an InnoDB
(http://dev.mysql.com/doc/refman/5.1/en/innodb-storage-en
gine.html) assertion was overly aggressive about
prohibiting an open range. (Bug #66513, Bug #14547952)
* Adding a LIMIT clause to a query containing GROUP BY and
ORDER BY could cause the optimizer to choose an incorrect
index for processing the query, and return more rows than
required. (Bug #54599, Bug #11762052)
* mysqlbinlog did not accept input on the standard input
when the standard input was a pipe. (Bug #49336, Bug
#11757312)