MySQL 5.5 Release Notes


This document contains release notes for the changes in each release of MySQL 5.5, up through MySQL 5.5.41. For information about changes in a different MySQL series, see the release notes for that series.

For additional MySQL 5.5 documentation, see the MySQL 5.5 Reference Manual, which includes an overview of features added in MySQL 5.5 (What Is New in MySQL 5.5), and discussion of upgrade issues that you may encounter for upgrades from MySQL 5.1 to MySQL 5.5 (Upgrading from MySQL 5.1 to 5.5).

Updates to these notes occur as new product features are added, so that everybody can follow the development process. If a recent version is listed here that you cannot find on the download page (, it means that the version has not yet been released.

The date mentioned with a release version is the date of the last revision control system changeset on which the release was based, not necessarily the date when the distribution packages were made available. The binaries are usually made available a few days after the date of the tagged changeset because building and testing all packages takes some time.

The documentation included in source and binary distributions may not be fully up to date with respect to release note entries because integration of the documentation occurs at release build time. For the most up-to-date release notes, please refer to the online documentation instead.

Previously, MySQL development proceeded by including a large set of features and moving them over many versions within a release series through several stages of maturity (Alpha, Beta, and so forth). This development model had a disadvantage in that problems with only part of the code could hinder timely release of the whole.

MySQL development now uses a milestone model. The move to this model provides for more frequent milestone releases, with each milestone proceeding through a small number of releases having a focus on a specific subset of thoroughly tested features. Following the releases for one milestone, development proceeds with the next milestone; that is, another small number of releases that focuses on the next small set of features, also thoroughly tested.

MySQL 5.5.0-m2 is the first release for Milestone 2. The new features of this milestone may be considered to be initially of beta quality. For subsequent Milestone 2 releases, we plan to use increasing version numbers (5.5.1 and higher) while continuing to employ the -m2 suffix. For Milestone 3, we plan to change the suffix to -m3. Version designators with -alpha or -beta suffixes are no used.

You may notice that the MySQL 5.5.0 release is designated as Milestone 2 rather than Milestone 1. This is because MySQL 5.4 was actually designated as Milestone 1, although we had not yet begun referring to milestone numbers as part of version numbers at the time.

For legal information, see the Legal Notices.

Document generated on: 2014-10-10 (revision: 4413)

Table of Contents

1 Preface and Legal Notices
2 Changes in MySQL 5.5.40 (2014-09-22)
3 Changes in MySQL 5.5.39 (2014-07-31)
4 Changes in MySQL 5.5.38 (2014-05-30)
5 Changes in MySQL 5.5.37 (2014-03-27)
6 Changes in MySQL 5.5.36 (2014-01-31)
7 Changes in MySQL 5.5.35 (2013-12-03)
8 Changes in MySQL 5.5.34 (2013-09-20)
9 Changes in MySQL 5.5.33 (2013-07-31)
10 Changes in MySQL 5.5.32 (2013-06-03)
11 Changes in MySQL 5.5.31 (2013-04-18)
12 Changes in MySQL 5.5.30 (2013-02-05)
13 Changes in MySQL 5.5.29 (2012-12-21)
14 Changes in MySQL 5.5.28 (2012-09-28)
15 Changes in MySQL 5.5.27 (2012-08-02)
16 Changes in MySQL 5.5.26 (Not released)
17 Changes in MySQL 5.5.25a (2012-07-05)
18 Changes in MySQL 5.5.25 (2012-05-30)
19 Changes in MySQL 5.5.24 (2012-05-07)
20 Changes in MySQL 5.5.23 (2012-04-12)
21 Changes in MySQL 5.5.22 (2012-03-21)
22 Changes in MySQL 5.5.21 (2012-02-17)
23 Changes in MySQL 5.5.20 (2012-01-10)
24 Changes in MySQL 5.5.19 (2011-12-08)
25 Changes in MySQL 5.5.18 (2011-11-16)
26 Changes in MySQL 5.5.17 (2011-10-19)
27 Changes in MySQL 5.5.16 (2011-09-15)
28 Changes in MySQL 5.5.15 (2011-07-28)
29 Changes in MySQL 5.5.14 (2011-07-05)
30 Changes in MySQL 5.5.13 (2011-05-31)
31 Changes in MySQL 5.5.12 (2011-05-05)
32 Changes in MySQL 5.5.11 (2011-04-07)
33 Changes in MySQL 5.5.10 (2011-03-15)
34 Changes in MySQL 5.5.9 (2011-02-07)
35 Changes in MySQL 5.5.8 (2010-12-03, General Availability)
36 Changes in MySQL 5.5.7 (2010-10-14)
37 Changes in MySQL 5.5.6 (2010-09-13, Release Candidate)
38 Changes in MySQL 5.5.5 (2010-07-06)
39 Changes in MySQL 5.5.4 (2010-04-09)
40 Changes in MySQL 5.5.3 (2010-03-24, Milestone 3)
41 Changes in MySQL 5.5.2 (2010-02-12)
42 Changes in MySQL 5.5.1 (2010-01-04)
43 Changes in MySQL 5.5.0 (2009-12-07, Milestone 2)