Join 29,000 others and follow Sean Hull on twitter @hullsean. Oh RDS, you offer such promise, but damn it if the devil isn’t always buried in the details. Diving into a recent project, I’ve been looking at upgrading RDS MySQL. Major MySQL upgrades can be a bit messy. Since the entire engine is rebuilt, queries […]

"Should vegetarians open steakhouse restaurants?"

Though someone will probably give me several examples of why they should, I'll argue that they absolutely should not. How can someone who doesn't eat steak convince others to eat at their "steak-only" restaurant?

But this is something a "professional technology benchmarker" (PTB) struggles with on a regular basis. Hello, I'm Tim Callaghan, and I'm a PTB.
professional technology benchmarker, or PTB (noun) : One who compares two technologies as part of their job. One of these technologies is usually the product of the PTB's employer, the other is almost always not. In a past experience I was tasked with comparing the performance of a fully in-memory database with Oracle and MySQL on a "TPC-C like" workload. At the time I was an Oracle expert and working for the in-memory database company, but had never started a single MySQL server in my life. At …

This is yet another story of Django web-framework with time zone support and pain dealing with python datetimes and MySQL on the backend. In other words, offset-naive vs offset-aware datetimes.

Shortly, more about the problem. After reading the official documentation about the time zones, it makes clear that in order to reflect python datetime in the necessary time zone you need to make it tz-aware first and than show in that time zone.

Here is the first issue: tz-aware in what time zone? MySQL stores timestamps in UTC and converts for storage/retrieval from/to the current time zone. By default, the current time zone is the server’s time, can be changed on MySQL globally, per connection etc. So it becomes not obvious what was tz of the value initially before stored in UTC. If you …

Twitter is not my favorite social media site. Using twitter is like driving downtown, screaming what you want to say out the window, and hoping someone hears you. There might be tens of thousands of people downtown, but your message will only be heard by a few. Your best bet is to repeat your message as often as possible.

However, twitter is free and if you want to reach as many people (theoretically) as possible, you might as well use it. But sending tweets on a scheduled basis can be a pain. There are client programs available which allow you to schedule your tweets (Hootsuite is one I have used in the past). You can load your tweets in the morning, and have the application tweet for you all day long. But you still have to load the application with your tweets – one by one.

A friend of mine asked me if there was a way to send the same 200 tweets over and over again, spaced out every 20 minutes or so. He has a consulting …

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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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 …

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 …