MySQL 5.1.21-rc が公開されました！

新機能満載の バージョン5.1系列の、RC版（リリース候補版)です。
ようやくRC版にたどり着いたということで、正式リリースが近づいている様子が感じられ、わくわくしますね。
前マイナーバージョン（5.1.20-beta)から1ヶ月強でのリリースということもあってか、修正点は少なめです。


http://dev.mysql.com/downloads/
からダウンロードすることができます。


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以下、チェンジログ


■機能の追加と変更(5.1.22-rc)
- 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


■バグ修正(5.1.22-rc)
- 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)