Since MariaDB aims to be a compatible/drop-in replacement to MySQL, its crucial that in 10.0 we support all the 5.6 options/system variables, else we have to clearly document them in the Knowledgebase article MariaDB versus MySQL – Compatibility.

To this extent, Sergey Vojtovich (svoj) has created MDEV-5277 as a tracker. There is also plenty of discussion on this topic at the maria-developers mailing list. I encourage current users of MySQL 5.6 to take a look at the list and comment either in Jira or on the mailing list to ensure that when …

November 19, 2013 By Severalnines

The Severalnines team is pleased to announce the release of ClusterControl 1.2.4. This release contains key new features along with performance improvements and bug fixes.

We have outlined some of the key features below. For additional details about the release:

• 1.2.4 ChangeLog
• Documentation
• Upgrade instructions
  • Manual upgrade instructions
  • …

The MariaDB project is pleased to announce the immediate availability of MariaDB 10.0.6. This is a Beta release. See the Release Notes and Changelog for detailed information on this release and the What is MariaDB 10.0? page in the AskMonty Knowledgebase for general information about the MariaDB 10.0 series.

Download MariaDB 10.0.6

Release Notes Changelog …

One of the most common errors in development is where a loop or a retrieval by index falls short or long by one unit, usually because of an oversight or a logic in coding.

Of the following snippets, which one will run 10 times?

/* #1 */    for (N = 0 ; N < 10; N++) printf("%d\n", N);

/* #2 */    for (N = 0 ; N <= 10; N++) printf("%d\n", N); 

/* #3 */    for (N = 1 ; N <= 10; N++) printf("%d\n", N);

/* #4 */    for (N = 1 ; N < 10; N++) printf("%d\n", N);

The question is deceptive, as there are two snippets that will run 10 times (1 and 3). But they will print different numbers. If you ware aiming for numbers from 1 to 10, only #3 is good.

After many years of programming, off-by-one errors are rare in my code, and I have been able to spot them or prevent them at first sight. That’s why I feel uneasy when I look at the way parallel replication is enabled in …

November 14, 2013 By Severalnines

Database schema changes are usually not popular among DBAs or sysadmins, not when you are operating a cluster and cannot afford to switch off the service during a maintenance window. There are different ways to perform schema changes, some procedures being more complicated than others. We invited Seppo from the Codership team to tell us about the options. If you’d like to learn more, please register for our new webinar.

Webinar: Galera Cluster Best Practices - Zero Downtime Schema Changes

Tuesday, December 3rd 2013

Register now - Europe/MEA/APAC

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Dan McKinley (Etsy) wrote an [IMHO] insightful article Why MongoDB Never Worked at Etsy.

First off, it’s important to realise that it’s not a snipe at MongoDB – it’s a fine tool.

The lessons are related to mixing multiple databases in a deployment (administration and monitoring overhead) and the acknowledgement that issues of schema design, scalability and maintenance need attention regardless of which brand or technology you pick for your database. That comes back to the old insight that migrations are rarely worth it (regardless of what you migrate to what).

I think these are indeed important considerations as they have a major impact on the ongoing costs of your entire environment (production as well as development and testing) – these days we encounter the “we’re doing this part of our application using MongoDB” …

Today before Ivan’s tutorial, he told me that in the 10.0.5 virtual machine images he created, he couldn’t find the Cassandra storage engine. I told him it had to be installed separately, and this is true – you have to install some engines separately!

When you do a yum install MariaDB-server MariaDB-client like the installation instructions tell you to do, you don’t get all storage engines (so running SHOW ENGINES might have you wondering what happened to a bunch of engines). This can easily be seen by doing a yum search MariaDB. On a CentOS 6.4 server with the MariaDB 10.0 repository configured, you should see the following:

MariaDB-cassandra-engine.x86_64 : MariaDB: a very fast and robust SQL database server
MariaDB-client.x86_64 : MariaDB: a very fast and robust SQL database server
MariaDB-common.x86_64 : MariaDB: a very fast and robust SQL …

There is a new feature in the MariaDB 10 Beta which caught my eye: support for returning a result set on delete.

With a 'regular' DELETE operation you only get to know the number of affected rows. To get more info or actions you have to use a trigger or a foreign key. Anoter posibility is doing a SELECT and then a DELETE and with the correct transaction isolation a transactional support this will work.

With the support for the RETURNING keyword this has become easier to do and it will probably bennefit performance and save you a few roundtrips and a few lines of code.

There is already support for RETURNING in PostgreSQL. And PostgreSQL has an other nifty feature for which RETURNING really helps: CTE or common table expressions or the WITH keyword. I really hope to see CTE support in MySQL or MariaDB some day.

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The slides and replay of yesterday’s webinar on the MariaDB CONNECT storage engine have just been posted. First I want to thank the numerous attendees. You have shown great interest on the parallel execution of query on distributed MySQL Servers. I agree this is cool. The ODBC capabilities seems also to generate interest. This make [...]

Yesterday was Melbourne Cup day in Australia – the biggest annual horse race event in the country, and in the state of Victoria it’s even a public holiday.

Open Query does work for Luxbet (part of Tabcorp), and Melbourne Cup day is by far their biggest day of the year in terms of traffic. It’s not just a big spike, there’s orders of magnitude difference so you can really say that the rest of the year is downright quiet (in relative terms). So, a very interesting load pattern.

Since last year Luxbet has upgraded from stock MySQL to MariaDB, and with our input made some other infrastructure modifications including moving to a pure solid state storage (FusionIO) solution as a SAN just won’t deliver the resilience and performance required. This may seem odd, but remember that a) …