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From:Joerg Bruehe Date:May 30 2012 7:17pm
Subject:MySQL Community Server 5.5.25 has been released
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Dear MySQL users,

MySQL 5.5.25 is a new version of the 5.5 production release of the
world's most popular open source database. MySQL 5.5.25 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
following resources:

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 5.5.25 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 5.5.25 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,
patches, etc.:

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
online at:


On behalf of the MySQL Build Team,
Joerg Bruehe

D.1.2. Changes in MySQL 5.5.25 (2012-May-30)

Functionality Added or Changed

  * The --safe-mode server option now is deprecated and will be
    removed in MySQL 5.6.

Bugs Fixed

  * Performance: InnoDB: Improved the algorithm related to
    adaptive flushing. This fix increases the rate of flushing in
    cases where compression is used and the data set is larger
    than the buffer pool, leading to eviction. (Bug #13990648, Bug

  * InnoDB: In a transaction using the REPEATABLE READ isolation
    level, an UPDATE or DELETE statement for an InnoDB table could
    sometimes overlook rows recently committed by other
    transactions. As explained in Section, "Consistent
    Nonlocking Reads," DML statements within a REPEATABLE READ
    transaction apply to rows committed by other transactions,
    even if a query could not see those rows. (Bug #14007649, Bug

  * InnoDB: The Innodb_buffer_pool_pages_flushed status variable
    was incorrectly set to twice the value it should be. Its value
    should never exceed the value of Innodb_pages_written. (Bug
    #14000361, Bug #65030)

  * InnoDB: The error handling and message was improved for
    attempting to create a foreign key with a column referencing
    itself. The message suggested a potential problem with the
    data dictionary, when no such problem existed. (Bug #12902967)

  * InnoDB: The CHECK TABLE statement could fail for a large
    InnoDB table due to a timeout value of 2 hours. For typical
    storage devices, the issue could occur for tables that
    exceeded approximately 200 or 350 GB, depending on I/O speed.
    The fix relaxes the locking performed on the table being
    checked, which makes the timeout less likely. It also makes
    InnoDB recognize the syntax CHECK TABLE QUICK, which avoids
    the possibility of the timeout entirely. (Bug #11758510, Bug

  * Replication: It was theoretically possible for concurrent
    execution of more than one instance of SHOW BINLOG EVENTS to
    crash the MySQL Server. (Bug #13979418)

  * Replication: Statements using AUTO_INCREMENT,
    LAST_INSERT_ID(), RAND(), or user variables could be applied
    in the wrong context on the slave when using statement-based
    replication and replication filtering server options (see
    Section 16.2.3, "How Servers Evaluate Replication Filtering
    Rules"). (Bug #11761686, Bug #54201)
    References: See also Bug #11754117, Bug #45670, Bug #11746146,
    Bug #23894.

  * Replication: An INSERT into a table that has a composite
    primary key that includes an AUTO_INCREMENT column that is not
    the first column of this composite key is not safe for
    statement-based binary logging or replication. Such statements
    are now marked as unsafe and fail with an error when using the
    STATEMENT binary logging format. For more information, see
    Section, "Determination of Safe and Unsafe Statements
    in Binary Logging," as well as Section, "Replication
    Tables using the InnoDB storage engine are not affected by
    this issue, since InnoDB does not allow the creation of a
    composite key that includes an AUTO_INCREMENT column, where
    this column is not the first column in the key.
    (Bug #11754117, Bug #45670)
    References: See also Bug #11761686, Bug #54201, Bug #11746146,
    Bug #23894.

  * SHOW TABLES was very slow unless the required information was
    already in the disk cache. (Bug #60961, Bug #12427262)

Joerg Bruehe,  MySQL Build Team,  joerg.bruehe@stripped
ORACLE Deutschland B.V. & Co. KG,   Komturstrasse 18a,   D-12099 Berlin
Geschaeftsfuehrer: Juergen Kunz     Amtsgericht Muenchen: HRA 95603
Komplementaerin: ORACLE Deutschland Verwaltung B.V. Utrecht, Niederlande
Geschaeftsfuehrer: Alexander van der Ven, Astrid Kepper, Val Maher

MySQL Community Server 5.5.25 has been releasedJoerg Bruehe30 May