发布于 2014-12-02 00:50:22 | 204 次阅读 | 评论: 0 | 来源: 网友投递
Mysql关系型数据库管理系统
MySQL是一个开放源码的小型关联式数据库管理系统，开发者为瑞典MySQL AB公司。MySQL被广泛地应用在Internet上的中小型网站中。由于其体积小、速度快、总体拥有成本低，尤其是开放源码这一特点，许多中小型网站为了降低网站总体拥有成本而选择了MySQL作为网站数据库。
MySQL是一个开放源码的小型关联式数据库管理系统，开发者为瑞典MySQL AB公司。MySQL被广泛地应用在Internet上的中小型网站中。由于其体积小、速度快、总体拥有成本低，尤其是开放源码这一特点，许多中小型网站为了降低网站总体拥有成本而选择了MySQL作为网站数据库。
MySQL 5.5.41 发布，此版本更新内容如下：
编译改进
移除了旧版本 Mac OS X 和 XCode 版本的 CMake 工作区 (Bug #18510941)
Previously, the MYSQL_MAINTAINER_MODE CMake option was turned on by default for debug builds and off for release builds, and MYSQL_MAINTAINER_MODE caused -Werror to be enabled when building with GCC. (Bug #18313717)
修改了构建支持，为 Clang 生成跟 gcc 一样的警告 (Bug #17959689)
CMake configuration for the Clang compiler sets more appropriate flags for building on Linux. Specifically, -g -fno-omit-frame-pointer -fno-strict-aliasing is now added. (Bug #17633291)
新功能和功能增强
新 -DWITH_UBSAN=ON CMake 选项允许 Undefined Behavior Sanitizer (Bug #19587393)
Bugs 修复
InnoDB: An ALTER TABLE operation raised an assertion. (Bug #19908343)
References: This bug is a regression of Bug #18806829.
InnoDB: In debug builds, setting the innodb_limit_optimistic_insert_debug debug configuration option to 1 caused an infinite B-tree page split. (Bug #19904003, Bug #74605)
InnoDB: The dict_set_corrupted() function attempted to update the clustered index of the SYS_INDEXES data dictionary table incorrectly. (Bug #19584379)
InnoDB: A procedure, called from a function to perform an operation on a temporary table, caused the server to halt. (Bug #19306524)
InnoDB: A CREATE TABLE operation that failed with innodb_strict_mode=ON would succeed without printing a warning with innodb_strict_mode=OFF. (Bug #17852083)
Replication: When using a MySQL version that had been compiled with the WITH_DEBUG option enabled, using expire_logs_days to purge binary logs caused a restart to crash the server. This problem arose after the fix for Bug #17283409. The fix ensures that current_thd is checked before calling DEBUG_SYNC(). (Bug #19553099)
Replication: A kernel mutex contention was being caused because mysqlbinlog was calling localtime() for every event read, which in turn called stat(/etc/localtime). (Bug #72701, Bug #18808072)
Replication: The global scope for the sql_log_bin system variable has been deprecated, and this variable can now be set with session scope only. (Bug #67433, Bug #15868071)
InnoDB permitted a foreign key to be created which referenced a parent table for which the user did not have sufficient privileges. (Bug #18790730)
On Windows, the replace utility did not work. (Bug #16581605)
On CentOS 6, specifying a relative path name for the --socket option caused MySQL startup script failure. (Bug #74111, Bug #19775856)
The IS_FREE_LOCK() and IS_USED_LOCK() function implementations contained a race condition due to which they could access freed memory when a user lock was concurrently checked and freed. (Bug #73123, Bug #19070633)
mysql_setpermission failed to properly quote user names in SQL statements that it generated. (Bug #66317, Bug #14486004)
同时还发布了 MySQL 5.6.22 版本，更新内容请看发行说明。