Percona Server 发布了 5.5.8-20.0 版本，这是对 MySQL 5.5.8 正式版的第一个增强版本，主要亮点有：

• 通过对服务器和存储引擎的改善提升了性能和可伸缩性
• 优化闪存存储，例如 SSD, Virident, and FusionIO
• 为元计算作出的优化
• 提供 HandlerSocket 插件用于 NoSQL 访问
• There’s an Amazon OS repository, as well as Yum and Apt repositories
• 改善了复制、分区和存储过程等功能
• 更详细的诊断和可调整性
• 更强的可嵌入式开发，包括可嵌入式的认证

在 MySQL 5.5 的基础上，详细的改进内容包括：

新功能

• InnoDB adaptive hash function searches can now be spread across multiple partitions (see  Multiple Adaptive Hash Search Partitions . Bug fixed:  #688866 . (Yasufumi Kinoshita)
• Information from  SHOW INNODB STATUS  was made available in new status variables in InnoDB Show Status . Bug fixed: #698797 .

变量更改

• New variable  innodb_adaptive_flushing_method  was added.
• New variable  innodb_use_global_flush_log_at_trx_commit  was added. Bug fixed: #635399 . (Yasufumi Kinoshita)
• New variable  log_warnings_silence  replaced old variable  suppress_log_warning_1592 . Bug fixed:  #692413 . (Oleg Tsarev)
• Old variable  innodb_adaptive_checkpoint  was deleted. Bug fixed:  #689450 . (Yasufumi Kinoshita)
• Old variable  innodb_flush_log_at_trx_commit_session  was deleted. Bug fixed:  #635399 . (Yasufumi Kinoshita)
• Old variable  use_global_long_query_time  was deleted. (Oleg Tsarev) Bug fixed:  #692415 .
• Old variable variable  innodb_ibuf_accel_rate  was renamed to  innodb_ibuf_merge_rate . Bug fixed:  #695906  (Yasufumi Kinoshita)
• Old variable variable innodb_ibuf_active_contract  was renamed to innodb_ibuf_active_merge . Bug fixed:  #695906  (Yasufumi Kinoshita)
• Old variable  enable_query_response_time_stats  was renamed to query_response_time_stats . (Oleg Tsarev)
• Existing variable  log_slow_verbosity  had two new values added: profiling  and profiling_use_getrusage . (Oleg Tsarev)
• Existing variables  profiling_server  and  profiling_use_getrusage  were merged into the Slow Query Log  page. (Oleg Tsarev)

其他更改

• Additional information was added to the  LOG  section of the  SHOW STATUS  command. Bug fixed:  #693269 . (Yasufumi Kinoshita)
• The  SHOW PATCHES  command was removed. (Vadim Tkachenko)
• The INFORMATION_SCHEMA table  XTRADB_ENHANCEMENTS  was removed. (Yasufumi Kinoshita)
• Several fields in the INFORMATION_SCHEMA table  INNODB_INDEX_STATS  were renamed. Bug fixed:  #691777 . (Yasufumi Kinoshita)
• The XtraDB version was set to 20.0. (Aleksandr Kuzminsky)
• Many InnoDB compilation warnings were fixed. Bug fixed: #695273 . (Yasufumi Kinoshita)
• An Amazon OS repository was created. Bug fixed:  #691996 . (Aleksandr Kuzminsky)

更多链接

• Downloads –  binary distributions  and  Percona Software Repositories
• Installation instructions
• Consulting ,  support ,  training , and  custom development
• Release notes
• Documentation
• Developer discussion group