Ideas, releases, practical guides, and perspectives from the people building with MySQL.
Today while browsing through my emails I was very happy to read this email from Sergei Golubchik :
Hi! I'm happy to announce that MariaDB-10.1 tree has been completely migrated to github. Since now on we'll use github for the new development in MariaDB. It's https://github.com/MariaDB/server, go on, fork it, hack around, submit pull requests. [...]
May 23, 2014 By Severalnines
If you need to deploy a database cluster behind your corporate firewall, on servers with no internet access, then this blog is for you. Most of the installation tutorials out there require servers to have an internet connection, and that would not work very well with companies under strict policies and compliance guidelines.
Our online Galera Configurator supports deployment
without Internet connection for Percona XtraDB Cluster. You would
need to prepare a minimum of four hosts (three DB nodes and one
management node), generate a Deployment Package from the
Configurator and copy it to the ClusterControl host. In this
post, we will show you how to deploy Percona XtraDB Cluster 5.5
in an environment without internet connection on CentOS 6.5
(installed with minimal installation). Our setup is …
MySQL 5.6 has added support for EXPLAIN FORMAT=JSON. The basic use case for that feature is that one can look at the JSON output and see more details about the query plan. More advanced/specific use cases are difficult, though. The problem is, you can’t predict what EXPLAIN FORMAT=JSON will produce. There is no documentation or any kind of convention regarding the contents of JSON document that you will get.
To make sure I’m not missing something, I looked at MySQL Workbench. MySQL Workbench has a feature called Visual Explain. If you want to use, prepare to seeing this a lot:
In Workbench 6.1.4 you get it for (almost?) any query with subquery. In Workbench 6.1.6 (released last week), some subqueries work, but it’s still easy to hit a query whose EXPLAIN JSON output confuses workbench.
Looking at the source code, this seems to be just the start of …
[Read more]If you couldn’t attend the MariaDB & MySQL Community Event in April 2014, held at the Hilton Santa Clara, fret not as there are slides and videos uploaded for you to watch at your leisure. There is likely to be at least one more community event later this year, so watch the space.
Currently on the page, you’ll find most of the talks with slides and the videos are professionally done – with slide overlays. The audio could be better on some, but for an event that was pulled together by Monty in less than 3 weeks, it’s not too shabby. You can learn What’s new in MariaDB 10, a little more about the SPIDER storage engine, more about the …
[Read more]May 19, 2014 By Severalnines
Thanks to everyone who attended and participated last week’s joint webinar on ClusterControl 1.2.6! We had great questions from participants (thank you), most of which are transcribed below with our answers to them.
If you missed the sessions or would like to watch the webinar again & browse through the slides, they are now available online.
Webinar topics discussed:
May 16, 2014 By Severalnines
We won’t bore you with buzzwords like volume, velocity and variety. This post is for MySQL users who want to get their hands dirty with Hadoop, so roll up your sleeves and prepare for work. Why would you ever want to move MySQL data into Hadoop? One good reason is archival and analytics. You might not want to delete old data, but rather move it into Hadoop and make it available for further analysis at a later stage.
In this post, we are going to deploy a Hadoop Cluster and export data in bulk from a Galera Cluster using Apache Sqoop. Sqoop is a well-proven approach for bulk data loading from a relational database into Hadoop File System. There is also Hadoop Applier available from …
[Read more]Recently, I was asked about an interesting case in ORDER BY … LIMIT optimization. Consider a table
create table tbl ( … KEY key1(col1, col2), PRIMARY KEY (pk) ) engine=InnoDB;
Consider queries like:
select * from tbl where col1=’foo’ and col2=123 order by pk limit 1; select * from tbl where col1=’bar’ and col2=123 order by pk limit 1;
These run nearly instantly. But, if one combines these two
queries with col1='foo' and col1='bar'
into one query with col1 IN ('foo','bar'):
select * from tbl where col1 IN (’foo’,'bar’) and col2=123 order by pk limit 1;
then the query is be orders of magnitude slower than both of the
queries with col1=const.
The first thing to note when doing investigation is to note that the table uses InnoDB engine, which has …
[Read more]
MariaDB 10.0 had a stable release last month. It is a good time
to take a look and see how it compares to the stable version of
MySQL, MySQL 5.6 (as for Percona Server, it doesn’t have its own
optimizer features).
Changelogs and release notes have all the details, but it’s
difficult to see the big picture. So I went for diagrams, and the
result is a short article titled What is the difference between MySQL and MariaDB
query optimizers. It should give one a clue about what are
the recent developments in query optimizers in MySQL world.
In case you’re interested in details about optimizer features in MariaDB 10.0, I’ve shared slides from a talk about MariaDB 10.0 query optimizer.
May 7, 2014 By Severalnines
Following the release of ClusterControl 1.2.6 a couple of weeks ago, we are now looking forward to demonstrating this latest version of the product on Tuesday next week, May 13th.
This release contains key new features (along with performance improvements and bug fixes), which we will be demonstrating live during the webinar.
Highlights include:
SAN JOSE, CA– May 6, 2014 – Continuent, Inc., a leading provider of open source database clustering and replication solutions, today announced that their recently announced Tungsten Replicator 3.0 solution has been certified by Cloudera, the leader in enterprise analytic data management powered by Apache Hadoop™. Continuent Tungsten Replicator 3.0 enables organizations to quickly and easily