The world's most popular open source database
Bugs fixed:
Important Change: Security Fix:
It was possible to circumvent privileges through the creation of
MyISAM tables employing the DATA
DIRECTORY and INDEX DIRECTORY
options to overwrite existing table files in the MySQL data
directory. Use of the MySQL data directory in DATA
DIRECTORY and INDEX DIRECTORY is
now disallowed. This is now also true of these options when used
with partitioned tables and individual partitions of such
tables.
(Bug#32167, CVE-2008-2079)
Incompatible Change:
There were some problems using DllMain()
hook functions on Windows that automatically do global and
per-thread initialization for
libmysqld.dll:
Per-thread initialization: MySQL internally counts the
number of active threads, which causes a delay in
my_end() if not all threads have
exited. But there are threads that can be started either by
Windows internally (often in TCP/IP scenarios) or by users.
Those threads do not necessarily use
libmysql.dll functionality but still
contribute to the open-thread count. (One symptom is a
five-second delay in times for PHP scripts to finish.)
Process-initialization:
my_init() calls
WSAStartup that itself loads DLLs and
can lead to a deadlock in the Windows loader.
To correct these problems, DLL initialization code now is not
invoked from libmysql.dll by default. To
obtain the previous behavior (DLL initialization code will be
called), set the LIBMYSQL_DLLINIT environment
variable to any value. This variable exists only to prevent
breakage of existing Windows-only applications that do not call
mysql_thread_init() and work
okay today. Use of LIBMYSQL_DLLINIT is
discouraged and is removed in MySQL 6.0.
(Bug#37226, Bug#33031)
Incompatible Change:
Some performance problems of
SHOW ENGINE INNODB
STATUS were reduced by removing used
cells and Total number of lock structs in row
lock hash table from the output. These values are now
present only if UNIV_DEBUG is defined at
MySQL build time.
(Bug#36941, Bug#36942)
Incompatible Change:
SHOW STATUS took a lot of CPU
time for calculating the value of the
Innodb_buffer_pool_pages_latched status
variable. Now this variable is calculated and included in the
output of SHOW STATUS only when
the UNIV_DEBUG symbol is defined at server
build time.
(Bug#36600)
Incompatible Change:
An additional correction to the original MySQL 5.1.23 fix was
made to normalize directory names before adding them to the list
of directories. This prevents /etc/ and
/etc from being considered different, for
example.
(Bug#20748)
See also Bug#38180

