Dear MySQL users,
MySQL 5.5.12 is a new version of the 5.5 production release of the
world's most popular open source database. MySQL 5.5.12 is recommended
for use on production systems.
MySQL 5.5 includes several high-impact enhancements to improve the
performance and scalability of the MySQL Database, taking advantage of
the latest multi-CPU and multi-core hardware and operating systems. In
addition, with release 5.5, InnoDB is now the default storage engine for
the MySQL Database, delivering ACID transactions, referential integrity
and crash recovery by default.
MySQL 5.5 also provides a number of additional enhancements including:
- Significantly improved performance on Windows, with various Windows
specific features and improvements
- Higher availability, with new semi-synchronous replication and
Replication Heart Beat
- Improved usability, with Improved index and table partitioning,
SIGNAL/RESIGNAL support and enhanced diagnostics, including a new
Performance Schema monitoring capability.
For a more complete look at what's new in MySQL 5.5, please see the
MySQL 5.5 is GA, Interview with Tomas Ulin:
Whitepaper: What's New in MySQL 5.5:
If you are running a MySQL production level system, we would like to
direct your attention to MySQL Enterprise Edition, which includes the
most comprehensive set of MySQL production, backup, monitoring,
modeling, development, and administration tools so businesses can
achieve the highest levels of MySQL performance, security and uptime.
For information on installing MySQL 5.5.12 on new servers, please see
the MySQL installation documentation at
For upgrading from previous MySQL releases, please see the important
upgrade considerations at:
MySQL Database 5.5 is available in source and binary form for a number
of platforms from our download pages at:
Not all mirror sites may be up to date at this point in time, so if you
can't find this version on some mirror, please try again later or choose
another download site.
We welcome and appreciate your feedback, bug reports, bug fixes,
The following section lists the changes in the MySQL source code since
the previous released version of MySQL 5.5. It may also be viewed
Changes in MySQL 5.5.12 (05 May 2011):
* InnoDB Storage Engine: Replication: Trying to update a column,
previously set to NULL, of an InnoDB table with no primary key
caused replication to fail with Can't find record in 'table'
on the slave. (Bug #11766865, Bug #60091)
* Replication: Using the --server-id option with mysqlbinlog
could cause format description log events to be filtered out
of the binary log, leaving mysqlbinlog unable to read the
remainder of the log. Now such events are always read without
regard to the value of this option.
As part of the fix for this problem, mysqlbinlog now also
reads rotate log events without regard to the value of
--server-id. (Bug #11766427, Bug #59530)
* InnoDB invoked some zlib functions without proper
initialization. (Bug #11849231)
* A missing variable initialization for Item_func_set_user_var
objects could cause an assertion to be raised. (Bug #59527,
* In Item_func_month::val_str(), a Valgrind warning for a
too-late NULL value check was corrected. (Bug #59166, Bug
* In Item::get_date, a Valgrind warning for a missing NULL value
check was corrected. (Bug #59164, Bug #11766124)
* In extract_date_time(), a Valgrind warning for a missing
end-of-string check was corrected. (Bug #59151, Bug #11766112)
* In string context, the MIN() and MAX() functions did not take
into account the unsignedness of a BIGINT UNSIGNED argument.
(Bug #59132, Bug #11766094)
* In Item_func::val_decimal, a Valgrind warning for a missing
NULL value check was corrected. (Bug #59125, Bug #11766087)
* In Item_func_str_to_date::val_str, a Valgrind warning for an
uninitialized variable was corrected. (Bug #58154, Bug
* SHOW EVENTS did not always show events from the correct
database. (Bug #41907, Bug #11751148)
MySQL RE Team
Bjorn Munch, MySQL Release Engineer
Database Group, Oracle.
|• MySQL Community Server 5.5.12 has been released||Bjorn Munch||9 May|