# MariaDB 5.2 Replication Feature Preview
**Note:** This page is obsolete. The information is old, outdated, or otherwise currently incorrect. We are keeping the page for historical reasons only. **Do not** rely on the information in this article.
This page describes a *"feature preview release"* which previewed some replication-related features which are included in [MariaDB 5.3](https://app.gitbook.com/s/aEnK0ZXmUbJzqQrTjFyb/community-server/old-releases/5.3/changes-improvements-in-mariadb-5-3). If you would like to try out the features mentioned here, it is recommended that you use [MariaDB 5.3](https://app.gitbook.com/s/aEnK0ZXmUbJzqQrTjFyb/community-server/old-releases/5.3/changes-improvements-in-mariadb-5-3) ([download MariaDB 5.3 here](https://downloads.askmonty.org/mariadb/5.3/)) instead of the actual release described below. Likewise, the code is available in the [MariaDB 5.3 tree on Launchpad](https://launchpad.net/maria/5.3).
## About this release
There has been\
quite a lot of interest in these features, and providing this feature preview\
release allows the developers to get more and earlier feedback, as well as\
allowing more users an early opportunity to evaluate the new features.
This feature preview release is based on [MariaDB 5.2](https://app.gitbook.com/s/aEnK0ZXmUbJzqQrTjFyb/community-server/old-releases/5.2/changes-improvements-in-mariadb-5-2), adding a number of fairly\
isolated features that are considered complete and fairly well-tested. It is\
however not a stable or GA release, nor is it planned to be so.
The stable\
release including these features will be [**MariaDB 5.3**](https://app.gitbook.com/s/aEnK0ZXmUbJzqQrTjFyb/community-server/old-releases/5.3/changes-improvements-in-mariadb-5-3). That being said, we\
greatly welcome any feedback / bug reports, and will strive to fix any issues\
found and we will update the feature preview until [MariaDB 5.3](https://app.gitbook.com/s/aEnK0ZXmUbJzqQrTjFyb/community-server/old-releases/5.3/changes-improvements-in-mariadb-5-3) stable is ready.
## Download/Installation
These packages are generated the same way as "official" MariaDB\
releases. Please see the [main download pages](https://mariadb.com/docs/server/clients-and-utilities/server-client-software/download) for more detailed\
instructions on installation etc.
The instructions below use the mirror [ftp.osuosl.org](https://ftp.osuosl.org/), but any of the MariaDB\
mirrors can be used by replacing the appropriate part of the URLs. See the [main download page](https://downloads.askmonty.org) for what\
mirrors are available.
### Debian/Ubuntu
For Debian and Ubuntu, it is highly recommended to install from the\
repositories, using `apt-get`, `aptitude`, or another favorite package\
managers.
First import the [public key](https://ftp.osuosl.org/pub/mariadb/PublicKey) with\
which the repositories are signed, so that `apt` can verify the integrity of\
the packages it downloads. For example, like this:
```bash
wget -O- http://ftp.osuosl.org/pub/mariadb/PublicKey | sudo apt-key add -
```
Now add the appropriate repository. An easy way is to create a file called`mariadb-5.2-rpl.list` in `/etc/apt/sources.list.d/` with contents like\
this for Debian:
```bash
deb http://ftp.osuosl.org/pub/mariadb/mariadb-5.2-rpl/debian squeeze main
deb-src http://ftp.osuosl.org/pub/mariadb/mariadb-5.2-rpl/debian squeeze main
```
Or this for Ubuntu:
```bash
deb http://ftp.osuosl.org/pub/mariadb/mariadb-5.2-rpl/ubuntu maverick main
deb-src http://ftp.osuosl.org/pub/mariadb/mariadb-5.2-rpl/ubuntu maverick main
```
Replace "squeeze" or "maverick" in the examples above with the appropriate\
distribution name. Supported are "lenny" and "squeeze" for Debian, and\
"hardy", "jaunty", "karmic", "lucid", and "maverick" for Ubuntu.
Now run
```bash
sudo apt-get update
```
The packages can now be installed with your package manager of choice, for\
example:
```bash
sudo apt-get install mariadb-server-5.2
```
(To manually download and install packages, browse the directories below- the .debs are in`debian/pool/` and `ubuntu/pool/`, respectively.)
### Generic Linux binary tarball
Generic linux binary tarballs can be downloaded here:
* i386 (32-bit):
* amd64 (64-bit):
### Centos 5 RPMs
* i386 (32-bit):
* amd64 (64-bit):
### Windows (32-bit)
*
### Source tarball
*
### Launchpad bzr branch:
* [lp:\~maria-captains/maria/mariadb-5.2-rpl](https://code.launchpad.net/~maria-captains/maria/mariadb-5.2-rpl)
## New Features in the [MariaDB 5.2](https://app.gitbook.com/s/aEnK0ZXmUbJzqQrTjFyb/community-server/old-releases/5.2/changes-improvements-in-mariadb-5-2) replication feature preview
Here is a summary of the new features included in this preview release. The\
headings link to more detailed information.
### [Group commit for the binary log](https://mariadb.com/docs/server/server-management/server-monitoring-logs/binary-log/group-commit-for-the-binary-log)
This preview release implements group commit which works when using XtraDB with\
the binary log enabled. (In previous MariaDB releases, and all MySQL releases at\
the time of writing, group commit works in InnoDB/XtraDB when the binary log\
is disabled but stops working when the binary log is enabled).
### [Enhancements for START TRANSACTION WITH CONSISTENT SNAPSHOT](https://mariadb.com/docs/server/ha-and-performance/standard-replication/enhancements-for-start-transaction-with-consistent-snapshot)
`START TRANSACTION WITH CONSISTENT SNAPSHOT` now also works with the binary\
log. This means it is possible to obtain the binlog position corresponding\
to a transactional snapshot of the database without blocking any other\
queries. This is used by `mysqldump --single-transaction --master-data` to do\
a fully non-blocking backup which can be used to provision a new slave.
`START TRANSACTION WITH CONSISTENT SNAPSHOT` now also works consistently\
between transactions involving more than one storage engine (currently XTraDB\
and PBXT support this).
### [Annotation of row-based replication events with the original SQL statement](https://mariadb.com/docs/server/clients-and-utilities/logging-tools/mariadb-binlog/annotate_rows_log_event)
When using row-based replication, the binary log does not contain SQL\
statements, only discrete single-row insert/update/delete *events*. This can\
make it harder to read mysqlbinlog output and understand where in an\
application a given event may have originated, complicating analysis and\
debugging.
This feature adds an option to include the original SQL statement as a\
comment in the binary log (and shown in mysqlbinlog output) for row-based\
replication events.
### [Row-based replication for tables with no primary key](https://mariadb.com/docs/server/ha-and-performance/standard-replication/row-based-replication-with-no-primary-key)
This feature can improve the performance of row-based replication on tables\
that do not have a primary key (or another unique key), but which do have another\
index that can help locate rows to update or delete. With this feature, index\
cardinality information from `ANALYZE TABLE` is considered when selecting the\
index to use (before this feature is implemented, the first index was selected\
unconditionally).
### [PBXT consistent commit ordering](https://mariadb.com/docs/server/ha-and-performance/standard-replication/enhancements-for-start-transaction-with-consistent-snapshot)
This feature implements the new commit ordering storage engine API in\
PBXT. With this feature, it is possible to use `START TRANSACTION WITH CONSISTENT SNAPSHOT` and get consistency among transactions which involve both\
XtraDB and InnoDB. (Without this feature, there is no such consistency\
guarantee. For example, even after running `START TRANSACTION WITH CONSISTENT SNAPSHOT` it was still possible for the InnoDB/XtraDB part of some\
transaction *T* to be visible and the PBXT part of the same transaction *T*\
to not be visible.)
### Miscellaneous
* This preview also includes a small change to make mysqlbinlog omit\
redundant `use` statements around `BEGIN`, `SAVEPOINT`, `COMMIT`,\
and `ROLLBACK` events when reading MySQL 5.0 binlogs.
* The preview included a feature [--innodb-release-locks-early](https://mariadb.com/docs/server/ha-and-performance/standard-replication/obsolete-replication-information/xtradb-option-innodb-release-locks-early). However, we\
decided to omit this feature from future MariaDB releases because of a\
fundamental design bug, [lp:798213](https://bugs.launchpad.net/maria/+bug/798213).
*This page is licensed: CC BY-SA / Gnu FDL*
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