オリジナル版：http://dev.mysql.com/doc/relnotes/mysql/5.5/en/news-5-5-39.html
MySQL 5.5.39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 5.5.39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:
http://dev.mysql.com/tech-resources/interviews/thomas-ulin-mysql-55.html
ドキュメント:
http://dev.mysql.com/doc/refman/5.5/en/mysql-nutshell.html
ホワイトペーパー: MySQL 5.5の新機能
http://dev.mysql.com/doc/refman/5.5/en/mysql-nutshell.html
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。
http://mysql.com/products/enterprise/
新しいサーバへMySQL 5.5.39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。
http://dev.mysql.com/doc/refman/5.5/en/installing.html
前回のMySQLリリースからアップグレードするには、以下のアップグレードについての注意事項を参照してください。
http://dev.mysql.com/doc/refman/5.5/en/upgrading-from-previous-series.html
MySQL Server 5.5.29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。
http://dev.mysql.com/doc/relnotes/mysql/5.5/en/news-5-5-39.html
Changes in MySQL 5.5.39 (2014-07-31)
Bugs Fixed * InnoDB: Opening an parent table that has thousands of child tables could result in a long semaphore wait condition. (Bug #18806829) * Partitioning: Selecting from a table having multiple columns in its primary key and partitioned by LIST COLUMNS(R), where R was the last (rightmost) column listed in the primary key definition, returned an incorrect result. (Bug #17909699, Bug #71095) * Replication: Quotation marks were not always handled correctly by LOAD DATA INFILE when written into the binary log. (Bug #18207212, Bug #71603) * Replication: A group of threads involved in acquiring locks could deadlock when the following events occurred: 1. Dump thread reconnects from slave; on master, a new dump thread tries to kill zombie dump threads; having acquired the thread's LOCK_thd_data, it is about to acquire LOCK_log. 2. Application thread executing show binary logs, having acquired LOCK_log and about to acquire LOCK_index. 3. Application thread executing PURGE BINARY LOGS; having acquired LOCK_index, it is about to acquire LOCK_thread_count. 4. Application thread executing SHOW PROCESSLIST (or SELECT * FROM INFORMATION_SCHEMA.PROCESSLIST), having acquired LOCK_thread_count and about to acquire the zombie dump thread's LOCK_thd_data. This leads to the 4 threads deadlocking in the same order which the threads have been listed here. This problem arises because there are ordering rules for LOCK_log and LOCK_index, as well as rules for ordering LOCK_thread_count and LOCK_thd_data, but there are no rules for ordering across these two sets of locks. This was because the internal mysqld_list_processes() function invoked by SHOW PROCESSLIST acquired LOCK_thread_count for the complete lifetime of the function as well as acquiring and releasing each thread's LOCK_thd_data. Now this function takes a copy of the threads from the global thread list and performs its traversal on these, and only after releasing LOCK_thread_count. During this traversal, removal from the global thread list is blocked using LOCK_thd_remove such that the copies that would otherwise be destroyed by the removal remain valid during traversal. The locking order following this fix is shown here: LOCK_thd_remove -> LOCK_thd_data -> LOCK_log -> LOCK_index -> LOCK_th read_count (Bug #17283409, Bug #69954) * SHA and MD5 functions failed for operations using the internal filename character set and could cause a server exit. (Bug #18786138) * (Bug #18715670) * Compiler flags were not passed to DTrace, causing problems for 32-bit builds cross-compiled on 64-bit platforms. (Bug #18593044) * mysqladmin password masked the old password given on the command line, but not the new password. (Bug #18163964) * yaSSL code had an off-by-one error in certificate decoding that could cause buffer overflow. yaSSL code had an opendir() without a corresponding closedir(). (Bug #18178997, Bug #17201924) * MyISAM temporary files could be used to mount a code-execution attack. (Bug #18045646) * If a query had both MIN()/MAX() and aggregate_function(DISTINCT) (for example, SUM(DISTINCT)) and was executed using Loose Index Scan, the result values of MIN()/MAX() were set improperly. (Bug #17217128) * For UNION statements, the rows-examined value was calculated incorrectly. This was manifest as too-large values for the ROWS_EXAMINED column of Performance Schema statement tables (such as events_statements_current). (Bug #17059925) * Use of a nonmulti-byte algorithm for skipping leading spaces in multi-byte strings could cause a server exit. (Bug #12368495, Bug #18315770) * Deadlock could occur if three threads simultaneously performed INSTALL PLUGIN, SHOW VARIABLES, and mysql_change_user(). (Bug #71236, Bug #18008907, Bug #72870, Bug #18903155) * MySQL did not compile with Bison 3. A workaround is to downgrade to Bison 2. (Bug #71250, Bug #18017820, Bug #18978946) * Uninstalling and reinstalling semisynchronous replication plugins while semisynchronous replication was active caused replication failures. The plugins now check whether they can be uninstalled and produce an error if semisynchronous replication is active. To uninstall the master-side plugin, there must be no semisynchronous slaves. To uninstall the slave-side plugin, there must be no semisynchronous I/O threads running. (Bug #70391, Bug #17638477) * If there was a predicate on a column referenced by MIN() or MAX() and that predicate was not present in all the disjunctions on key parts earlier in the compound index, Loose Index Scan returned an incorrect result. (Bug #71097, Bug #17909656) * File permissions and line endings of several test and configuration files were made more consistent to avoid warnings from package checkers. (Bug #68521, Bug #16415173, Bug #16395459, Bug #68517, Bug #16415032, Bug #71112, Bug #17919313, Bug #71113, Bug #17919422