OK! So, the new mysqlcamp.org website and wiki is now up and running. Many thanks go out to the guys at PeanutButter Wiki, who graciously allowed us an enterprise edition version of pbwiki so that we could use the mysqlcamp.org website unhindered. You guys rock!

Also, many more thanks to Kevin Burton, the CEO of Tailrank, for his help over the last week in contacting pbwiki and helping with some setup. As you can see on the wiki, we've got a few sponsors already, and things look pretty good to make this a fantastic inaugural MySQL camp. We're aiming for around 100 developers and users, with a …

One of my colleagues recently redesigned a system for scheduling work, and needed to write a multiple-table UPDATE with ORDER BY and LIMIT, neither of which is supported for multiple-table UPDATE in MySQL. This article explains how to do it anyway, and shows how to rewrite a first attempt for hundreds of times better performance. Introduction Without revealing too much about my employer’s internal systems, I want to give a little bit of context.

I’ve released another version of the innotop MySQL and InnoDB monitor. It’s worth upgrading to this version not only because of the new features, but also because it should handle more special cases without crashing. Of course, if it does crash, I appreciate your help fixing it; see this article about what information I need. Changes since version 0.1.123 include: Fixes to deal with older versions of Perl. Thanks to everyone who helped me find out what was wrong.

A new and updated version of the Zend PHP Certification is on the way and will be available starting August, 31st:

Zend PHP 5 Certification Page

It's a complete rewrite, but the exam will still (as with the PHP 4 exam) cover 70 questions in 90 minutes. A new Study Guide will be available starting September and current PHP 4 certified people will get a discount for the PHP 5 exam.

To get detailed information, you can also listen to the Webcast Recordings at the phparch.com website.

And for those who prefer taking a MySQL 5 certification, there's also information available for …

Here's another good rule about using MySQL in your application:

Never let your application access the MySQL server with a user that has SUPER privileges (at least unless there's a VERY good reason to do it).

There may be more reasons for that but one is that it might stop your root user from accessing the server if all allowed connections are being used (the "Too many connections" error).

Here's what the manual says:

"mysqld actually allows max_connections+1 clients to connect. The extra connection is reserved for use by accounts that have the SUPER privilege. By granting the SUPER privilege to administrators and not to normal users (who should not need it), an administrator can connect to the server and use SHOW PROCESSLIST to diagnose problems even if the maximum number of unprivileged …

Jay Pipes continues cache experiements and has compared performance of MySQL Query Cache and File Cache.

Jay uses Apache Benchmark to compare full full stack, cached or not which is realistic but could draw missleading picture as contribution of different components may be different depending on your unique applications. For example for application containing a lot of clode but having only couple of queries to MySQL parsing may be performance bottleneck, assuming PHP opcode cache is not used. Also different applications may have different cache hit ratios which also needs to be factored in estimating improvement for real application.

So instead of following his route, especially as Jay is going to publish his comparison of all caches anyway, I decided to check peak performance of all caches compared to …

Open source projects have a lot of documentation. Some professionally written, others community contributed. One thing that community contributed documentation has going for it is the passionate users that write localized content.

Localization of documentation is important. While we take it for granted that we all speak/read/write/understand the English language, a lot of people just starting out in non-English speaking areas might find it useful to read some localized content. Hook them based on their interests, and slowly they can be weaned off to other non-localized documentation, and might contribute to the localizing cause eventually, even.

Localization is also not easy. If you tried to localize the MySQL Documentation, …

I've been using a home grown scripting language called Raven for a couple of years now. I think it is a good tool for working with MySQL, particularly when one needs to crank out a quick script on the fly using simple and readable code. Currently it spends a lot of time talking to my cluster. Here are the basics...

Connect to the Database:

'mysql://user:password@localhost/test' open as $mysql 

Select some records:

'SELECT * FROM mytable' $mysql query as $result 

Get the number of selected records:

$result selected as $num_rows 

Iterate over the result set and output a CSV:

$result each as $record 
    $record ',' join print "\n" print 

Insert a record and return the last AUTO_INCREMENT value …

Why would you ever want to deliberately cause a deadlock? Sometimes a very large deadlock in MySQL will fill the output of SHOW ENGINE INNODB STATUS until it truncates, so you can't see information about transactions, log and I/O, buffers, and so forth. I know only two solutions to this problem: 1) restart MySQL and 2) cause a small deadlock so the LAST DETECTED DEADLOCK section shrinks to an acceptable size. In this article I'll show you how to cause a small deadlock, and how to use innotop to do it more easily.

This article is part of a series on how to use innotop to make your life easier.

Yes, that's right. You can start looking for airborne swine! We have released the first drop of Connector/Net 5.0! While there were reasons why this release took so long to get out, I'll take a page from Ballmer's book and commit to you that it won't happen again. In any case, this release has lots of goodies baked in.

• ADO.Net 2.0 support
• Usage Advisor
• PerfMon hooks
• Completely virtualized execution pipeline (this will support use of the client library and embedded server later)
• Faster execution
• Type safe methods on MySqlDataReader completely avoid value boxing
• Procedure metadata caching
• New option for not resetting the connection on pool checkout
• And much more!

There are a few things broken or missing in this first code drop. Here is the current list.

• Connecting via shared memory or using …