And so last night Arsenal's Champions League season ended in a brilliant match which ended the completely wrong way. Arsenal's problem is clear: it's incredibly slick passing and footwork results in too few goals. (Stay with me here - this really is an open source post.)

But that doesn't really tell the story. The real story behind Arsenal's problems sounds eerily similar to Clay Christensen's Innovator's Dilemma. And, hence, Arsenal's problem is much like the software industry's problem.

Arsenal has dominated (off and on) English football for nearly 100 years. In 2004-05, the team went 49 games without being beaten. At the heart of its recent success is Thierry Henry, the world's best forward. In years past, Henry put in more goals than anyone else in the league, in striking and beautiful fashion.

This year? Not even a …

Been hacking on the MySQL Forge over the last week or so... The biggest change is that, thanks to many folks, notably Peter Gultzan and Lenz Grimmer, our internal Worklog system is now publicly available — and commentable — on MySQL Forge.

What's the Big Deal With That, Jay?

Well, lots of folks want to see the "roadmap" which the MySQL development team follows. Worklog, and specifically the Worklog (WL) tasks, are about the closest thing to a fluid, documented internal development roadmap that you can get.

Right now, there are 854 public tasks available for searching and commenting on the Forge, and more will be popping up every day, as development teams within MySQL open up their tasks for public commenting.

Got An Idea? Tell a Dev!

If you've got ideas, or …

By Tim O'Reilly

As some of you have probably already noted, I recently joined the MySQL board. There are a couple of good reasons.

First, MySQL has a unique position at the juncture of two of my abiding interests, open source and Web 2.0. As I wrote in the quote that I provided for the press release: "The platforms powering the Web today are the enterprise infrastructure of tomorrow. What we learn from those platforms is the enormous power of open source, open standards, and user involvement ... and one more thing -- that the future belongs to data. Every killer app on the Internet is a database application. And that makes MySQL the 'Intel Inside' of the next-generation of computer applications."

It's not every open source project that gets to be part of the acronym …

Are you seeing a MySQL error that says InnoDB support isn't enabled, even though it is? This article explains why it happens and how to fix it.

The way InnoDB handles locking of the Buffer Pool has been changed with 5.0.30. Sites that have a large (16GB+) innodb_buffer_pool_size and high concurrency (4+ CPUs) will experience lock contention of the single global Buffer Pool lock in older versions of MySQL. In Cacti that behavior can look like this:

5.0.26, high InnoDB load, memory saturated environment (database smaller than RAM), very high concurrency.

CPU usage >100% not plotted properly, thus the strange graph. Watch the high system time consumption.

After upgrading from 5.0.26 to 5.0.36, the lock contention goes away. The gain materializes itself as a greatly reduced system time usage.

5.0.36, high InnoDB load, memory saturated, high concurrency.

User time comparable, system time a lot smaller.

It has been very productive this week working at Brian's place in Seattle. No sightseeing this trip but had an enjoyable experience talking with other developers and users at the MySQL meetup session.
I have been working on developing a flexible Log Plugin system which hopefully does not have the drawbacks of the existing system. The new code seems to be working well now although it is not tied into any system variables in a way to show off what it can do. My patch earlier on Wednesday replaced about 2500 LOC with about 500. Even after the code written today, there is still a significant reduction in the overall code size. Now, all I need is my plugin server variables patch pushed...

Open Source software is often being referred to as commodity products. This is particularly true for OSS databases like MySQL or PostgreSQL. Developers of such systems can heavily make use of defined standards. In this case, it’s the various SQL standards. These standards define the general functionality set your product should have. They help you define the commodity features of your software.

The question is: where do you get your software requirements from if the OSS product you are developing cannot rely on any or only a few standards?

Let’s take a look at two other types of OSS products: Enterprise Content Management (ECM) and collaborative software. I used to work for an Open Source ECM vendor until recently and just …

I reckon that techies sometimes go overboard in accuracy!
Many sites use so-called Great-Circle calculations to find places within a certain distance of a specified location. The resulting queries tend to do full table scans with relatively few actual matches, then order by distance and page or limit that.

If, instead, you use a bounding rectangle and also pretend that earth is flat, life becomes much easier. The resulting queries then will use range scans on indexes. So much faster you wouldn't believe it.

What's the difference? Well, accuracy.
For short distances, the earth's curvature is not significant.
Apart from that, the maximum deviation from the radius is (SQRT(POWER(r,2) * 2) - r) where r is the radius, simply applying Pythagoras' Theorem.
It comes down to a deviation of about 20 kilometers when looking in …

For those that follow Daylight Savings Time in the US and Canada, watch out this weekend, because we “spring forward”!

The biggest caveat I have is: Do not arrive 1 hour late to work on Sunday or Monday.

As for MySQL, to test if you are fine, run:

SELECT @@global.time_zone;

If you get back “SYSTEM”, then MySQL is looking to the OS for timezone data, which is the default.

The real sanity check:

SELECT UNIX_TIMESTAMP('2007-03-11 02:00:00'), UNIX_TIMESTAMP('2007-03-11 03:00:00');

This should return the same value, even though you are feeding it different times, because this is when the 1 hr change occurs. If not, and you’ve played with timezone data, remember that timezone data is only loaded when MySQL starts, so if you haven’t restarted MySQL since you patched your OS, you need to do that.

This is mostly stolen from a MySQL list post I found …

Do you hate it when you execute a query in the mysql cli only to have the output wrap three times making it almost impossible to read? Do you end up re-executing the query with \G waiting once again for the query to run? Well wait no more! My very first submitted patch to mysql is a client patch that adds –auto-vertical-output. This option compares the width of your terminal to the width of the result set and enables vertical output if it’s going to wrap. The patch link and details are Bug #26780