MySQL 5.5.28 がリリースされました


MySQL 5.5.28は世界でもっともポピュラーなオープンソースデータベースの5.5のプロダクトリリースの新しいバージョンです。MySQL 5.5.28はプロダクションシステムでの使用をお勧めします。


MySQL 5.5は最新のマルチCPUやマルチコアハードウェアやオペレーティングシステムの利点を生かし、MySQLデータベースのパフォーマンスとスケーラビリ ティを改善するための影響の大きい変更をいくつか含んでいます。現在ではInnoDBがMySQLデータベースのデフォルトのストレージエンジンであり、 ACIDトランザクション、参照整合性、クラッシュリカバリをデフォルトで提供しています。

MySQL 5.5は以下の多くの新しい強化も含んでいます:

   - Windowsにおける特有の機能と改善を利用した著しいパフォーマンス向上
   - 新しい準同期レプリケーションとレプリケーションハートビートによるより高いレベルの可用性
   - 改善されたインデックスとテーブルパーティショニング、SIGNAL/RESIGNALサポート、そして新しいPERFORMANCE_SCHEMAに含まれる強化された診断法による改善されたユーザビリティ

MySQL 5.5の新機能のより完全な概観については、以下のリソースを参照下さい。

MySQL 5.5 GA、Tomas Ulinのインタビュー:




ホワイトペーパー: MySQL 5.5の新機能


製品レベルのシステムでMySQLを稼動させているならば、MySQL製品、バックアップ、モニタリング、モデリング、開発、管理ツールの包括的なセット を含むMySQLパフォーマンス、セキュリティ、アップタイムの高いレベルを実現するMySQL Enterprise Editionの製品詳細に注目してください。


新しいサーバへMySQL 5.5.28をインストールする情報として、以下のMySQLのインストールドキュメントを参照してください。





MySQL Server 5.5.28は、http://dev.mysql.com/downloads/とミラーサイトのダウンロード・ページから、ソースコード及び多くのプラットフォームのためのバイナリで現在利用可能です。


次の節では、MySQL 5.5の以前のバージョンからの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できます。

Changes in MySQL 5.5.28 (2012-September-28)

Functionality Added or Changed

   * The internal interface of the Thread Pool plugin has changed.
     Old versions of the plugin will work with current versions of
     the server, but versions of the server older than 5.5.28 will
     not work with current versions of the plugin.

Bugs Fixed

   * InnoDB: Certain information_schema tables originally
     introduced in MySQL 5.6 are now also available in MySQL 5.5
     INNODB_BUFFER_POOL_STATS. (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 and REPEATABLE READ. (Bug #11765218)

   * Partitioning: For tables using PARTITION BY HASH or PARTITION
     BY KEY, when the partition pruning mechanism encountered a
     multi-range list or inequality using a column from the
     partitioning key, it continued with the next partitioning
     column and tried to use it for pruning, even if the previous
     column could not be used. This caused partitions which
     possibly matched one or more of the previous partitioning
     columns to be pruned away, leaving partitions that matched
     only the last column of the partitioning key.
     This issue was triggered when both of the following conditions
     were met:

       1. The columns making up the table's partitioning key were
          used in the same order as in the partitioning key
          definition by a SELECT statement's WHERE clause as in the
          column definitions;

       2. The WHERE condition used with the last column of the
          partitioning key was satisfied only by a single value,
          while the condition testing some previous column from the
          partitioning key was satisfied by a range of values.
     An example of a statement creating a partitioned table and a
     query against this for which the issue described above
     occurred is shown here:
       CREATE TABLE t1 (
       c1 INT,
       c2 INT,
       PRIMARY KEY(c2, c1)
       ) PARTITION BY KEY()  # Use primary key as partitioning key
       PARTITIONS 2;

       SELECT * FROM t1 WHERE c2 = 2 AND c1 <> 2;
     This issue is resolved by ensuring that partition pruning
     skips any remaining partitioning key columns once a partition
     key column that cannot be used in pruning is encountered. (Bug

   * 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
     tml)). (Bug #13025132)
     References: See also Bug #11764622, Bug #14537277.

   * Replication: On 64-bit Windows platforms, values greater than
     4G for the max_binlog_cache_size and
     max_binlog_stmt_cache_size system variables were truncated to
     4G. This caused LOAD DATA INFILE to fail when trying to load a
     file larger than 4G in size, even when max_binlog_cache_size
     was set to a value greater than this. (Bug #13961678)

   * Replication: In master-master replication with
     --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 not to be updated. (Bug #13596613)

   * The RPM spec file now also runs the test suite on the new
     binaries, before packaging them. (Bug #14318456)

   * 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)

   * The Thread Pool plugin did not respect the wait_timeout
     timeout for client sessions. (Bug #13699303)

   * CHECK TABLE and REPAIR TABLE could crash if a key definition
     differed in the .frm and .MYI files of a MyISAM table. Now the
     server produces an error. (Bug #13555854)

   * A query for a FEDERATED 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

   * mysqlhotcopy failed for databases containing views. (Bug
     #62472, Bug #13006947, Bug #12992993)

   * The argument to the --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)

   * 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)