Databases Reference
In-Depth Information
MariaDB
After Sun's MySQL acquisition Monty Widenius, the cofounder of MySQL, left Sun
Microsystems over disagreements about the MySQL development process. He founded
Monty Program AB and created MariaDB to foster an “open development environment
that would encourage outside participation.” MariaDB's goals are community devel-
opment, along with bug fixes and lots of new features—especially integration of com-
munity-developed features. To quote Monty again,
2
“the vision for MariaDB is for it
to be user and customer driven, as well as more inclusive of community patches and
plugins.”
What's different about MariaDB? As compared to Percona Server, it includes much
more extensive changes to the server. (Most of Percona Server's big changes are in the
Percona XtraDB storage engine, not the server level.) There are many changes to the
query optimizer and replication, for example. And it uses the Aria storage engine for
internal temporary tables (those used for complex queries, such as
DISTINCT
or subqu-
eries) instead of MyISAM. Aria was originally named Maria, and was intended as an
InnoDB replacement during the uncertain Sun times. It is essentially a crash-safe version
of MyISAM.
In addition to Percona XtraDB and Aria, MariaDB also includes a number of commu-
nity storage engines, such as SphinxSE and PBXT.
MariaDB is a superset of stock MySQL, so existing applications should keep working
with no changes, just as with Percona Server. However, MariaDB will work much better
for some scenarios, such as complex subqueries or many-table joins. It also features a
segmented MyISAM key cache, which makes MyISAM much more scalable on modern
hardware.
Perhaps the finest work in MariaDB, however, is in MariaDB 5.3, which is in Release
Candidate status at the time of writing. This version includes an enormous amount of
work on the query optimizer—probably the biggest optimizer improvements MySQL
has seen in a decade. It adds new query execution plans such as hash joins, and fixes
many of the things we've pointed out as weaknesses in MySQL throughout this topic,
such as outside-in subquery execution. It also includes significant extensions to the
server, such as dynamic columns, role-based access control, and microsecond time-
stamp support.
For a more complete list of improvements to MariaDB, you can read the documentation
on
http://www.askmonty.org
or these web pages that summarize the changes:
http://
2. The quotes are from
http://monty-says.blogspot.com/2009/02/time-to-move-on.html
and
http://monty-says
