This is a follow-up post to my recent announcement of only_full_group_by improvements in 5.7, where I’d like to address some tricky corner cases where GROUP BY contains non-column expressions (functions).

In the SQL standard, GROUP BY should contain only table columns and never expressions. So this example query where we want to count how many people have the same name is illegal in the SQL2011 standard because the GROUP BY clause contains a function:

CREATE TABLE people (first_name VARCHAR(100), last_name VARCHAR(100));

SELECT CONCAT(first_name, ' ', last_name), COUNT(*)
FROM people
GROUP BY CONCAT(first_name, ' ', last_name);

But MySQL does allow expressions in a GROUP BY clause, and it’s a very convenient addition to the standard. The logic …

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We have presentations for any level, from beginner to advanced. You’ll learn about the backend and frontend, web and mobile, information systems and games, hard and soft skills, as well as many related topics.

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If your goal is to learn and meet interesting people, then ConFoo is the conference for you! Take advantage of our $190 early bird …

Imagine that two colleagues, Alice and Bob, issue a command to launch a new virtual machine at approximately the same moment in time. Both Alice’s and Bob’s virtual machines must be given an IP address within the range of IP addresses granted to their project. Let’s say that range is 192.168.20.0/28, which would allow for a total of 16 IP addresses for virtual machines [1]. At some point during the launch sequence of these instances, Nova must assign one of those addresses to each virtual machine.

How do we prevent Nova from assigning the same IP address to both virtual machines?

In this blog post, I’ll try to answer the above question and shed some light on issues that have come to light about the way in which OpenStack projects currently solve (and sometimes fail) to address this issue.

Demonstrating the …

I'm starting off 2015 with the following New Year's Resolution, to improve the state of benchmarking. About a month ago I noticed the following tweet:
Hey @tokutek, please look at this: http://stssoft.com/products/stsdb-4-0/benchmark …. Are the benchmarks rigged or correctly done? I'm curious to know! While I've never met Ian Campbell (@iamic) he certainly knew how to call me to action. I immediately checked out the STSsoft website, the benchmark results page, and the benchmark code itself. My first reaction …

We have been using SHOW ENGINE INNODB MUTEX command for years. It shows us mutex and rw-lock information that could be useful during service troubleshooting in case of performance problems. As Morgan Tocker announced in his blog post the command will be removed from MySQL 5.7 and we have to use performance_schema to get that info.

The documentation of MySQL also says that most of the command output has been removed from 5.6 and that we can find similar info in performance_schema. It doesn’t show any examples of how to use performance_schema or what is the query we need to use from now on. It is also important to mention that 5.6 doesn’t show any warning about the feature being deprecated.

This is a short blog post to show how to configure performance_schema and get the info we need. Hoping it will end …

It’s a new year, and that means there are new challenges in the ever shifting technology landscape. Begin 2015 ahead of the curve. On January 22nd, StackScope will host its first webinar, an industry roundtable. Four industry leaders will discuss topics including the Cloud, Big Data, Microservices, Continuous Delivery, Containerization, and the Internet of Things. They will address questions from the future of DevOps to the impact of Amazon Aurora and everything in between. You do not want to miss the opportunity to participate with these tech vets:

• Adrian Cockcroft, World-renowned Cloud Computing and Performance Optimization expert, author, and Technology Fellow for the investment firm …

#DBHangOps 01/08/15 -- More Compression!

Hello everybody!

Join in #DBHangOps this Thursday, January, 08, 2015 at 11:00am pacific (18:00 GMT), to participate in the discussion about:

• More compression!
• MySQL Event Scheduler
• What is everyone's understanding of innodb_io_capacity?

You can check out the event page at https://plus.google.com/events/cb7pdn3egenc6c79lc4bc74kr04 on Thursday to participate.

As always, you can still watch the #DBHangOps twitter search, the @DBHangOps twitter feed, or this blog post to get a link for the google hangout on Thursday!

See all of you on Thursday!

You …

In this blog post I will describe different ways of using SSL with the MySQL database server.

What does SSL give you?

You might use MySQL replication over the internet or connect to MySQL over the internet.

Another posibility is that you connect over an enterprise network to which just too many people have access. This is especially an issue if you use an BYOD network.

SSL helps here by encrypting the network traffic to prevent against evesdropping. It also validates that you're talking to the correct server to prevent man-in-the-middle attacks.

And you can also use SSL client certificates together with an password as two factor authentication.

SSL is not the only option, you could use SSH and many MySQL GUI clients like MySQL Workbench support …

Hi, all. Just a quick note to let you all know that we completed the move of MySQL Server development from Bazaar to Git some time ago. This means that as of the upcoming, end of January batch of Server releases (5.6.23 and 5.5.42), our official source code hosting moves from Launchpad to GitHub. The […]

In MySQL 5.6, one of the most well received changes was improving the default configuration to be safer, and easier to use.

We are seeking community feedback for improvements that can be made to the default configuration in MySQL 5.7. Please leave a comment, or get in touch with me via email.

For elimination of confusion, please state both the setting you would like changed, and the new desired value.

Thanks!