OK, so we're going to get pretty down-and-dirty in the C source code that handles concurrent inserts... you've been warned. For background on the MyISAM concurrent insert functionality, see my previous article. Before I get going, I'd like to give a big shout out and thank you to Ingo Strüwing and Sergei Golubchik, whose comments and insight on the MySQL internals mailing list helped me keep from exploding while digging through the source code. Ingo and Serg are great resources that any developer looking to better understand the MySQL sources should be grateful to have around.

The way I approached delving into the concurrent insert functionality was actually quite different from the way I looked at the overall MySQL server architecture in Pro MySQL. When writing the book, I relied heavily on the …

And again we're on our mission to keep XAMPP up-to-date and put the first beta version of the upcoming XAMPP release in our public beta download area.

In this beta we updated: PHP 5 (to 5.2.3), MySQL (to 5.0.45), and phpMyAdmin (to 2.10.2).

Get the downloads at XAMPP BETA.

XAMPP beta versions are always for testing purposes only. There will be no upgrade packages from and to beta versions. To all testers: Many thanks in advance!!

Many businesses are now interested in implementing MySQL Cluster as a general high availability solution for their existing databases. This is certainly not a good approach and will often fail due to the limitations currently in the MySQL Cluster implementation (particularly 5.0) and the type of data within the business. However, many are still seeing MySQL Cluster as a magical solution to take out their potential downtime instead of other standard measures such as DRBD, multimaster or scale-out replication.

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Many businesses are now interested in implementing MySQL Cluster as a general high availability solution for their existing databases. This is certainly not a good approach and will often fail due to the limitations currently in the MySQL Cluster implementation (particularly 5.0) and the type of data within the business. However, many are still seeing MySQL Cluster as a magical solution to take out their potential downtime instead of other standard measures such as DRBD, multimaster or scale-out replication.

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So, we are not officially looking for PHP/MySQL developers.  However, we could start at any moment.  So, I want to be ready.  There is a really good chance that we will hire someone by the end of the year if not sooner.

So, if you want to work with an up and coming company that uses PHP, MySQL, Gentoo Linux and other open source technology, you can go ahead and send us a resume.  Just email it to me at brianm@dealnews.com.  You will have to confirm your emails.  Spam on that account reach huge numbers years ago, so I am not going to bother with cute notation for my email address.

This job would most likely require moving to Huntsville, AL.  Before you make an Alabama joke, Huntsville has been recognized as a great place for business and technology.  In 2006 it was …

Matt asks (almost as an aside to a post on a related topic): My question: why not just buy Red Hat? Before Red Hat buys MySQL, and gives those database numbers a run for their money? Then, Larry Dingnan writes: A Credit Suisse analyst thinks BEA Systems is likely to go on the auction block in the next three to six months. And the potential buyer is two likely suspects: Private equity firms or Oracle, which indicated it has no plans to slow down its acquisition pace. I'll play Nostradamus and predict that Oracle will not buy Red Hat. Oracle... READ MORE

OK, so you have a nice replication setup, but how do you know it is actually working, and what do you do when it stops? This short article shows how to check and quickly fix replication that has stopped. This procedure takes 2 minutes and can be done remotely on the command line.

Back in February I wrote about the release of Yahoo! Pipes (see Yahoo! Pipes: Unlocking the Data Web):

So if you're interested in an interactive on-line data mashup construction set, check it out and have a look at the existing pipes developers have created. I think it's one of the coolest web apps we've released in a long time, and I'm not just saying that because I know the guys who built it. Not only does it make hard things easy (like Perl has done for years), the user interface kicks ass too. It's exciting both from a technological point of view and because of the implications for the web as a whole.

Since February, Pipes has been growing and improving (see the Pipes blog) and the …

Max Mether pointed out an error in something I mentioned last week in a performance tuning webinar and I wanted to clarify and correct. In the webinar I said that concurrent inserts would only be available on a MyISAM table if an AUTO_INCREMENT primary key was used. That's incorrect. I was confusing the concurrent_insert server variable with the AUTO_INCREMENT property. I should have just re-read my own book, which covers the topic in some detail in Chapter 5. Oh well.

But, in case you missed the webinar or just aren't aware of what concurrent insert is, let me explain. First, some background information on MyISAM.

MyISAM and Table-Level Locks

Unlike InnoDB, which employs row-level locking, MyISAM uses a much coarser-grained locking system to ensure …

How does Buffer Pool size affects Innodb Performance ? I always expected the effect to be positive, Innodb with large buffer pool to performing better. Including Recovery of course. I even blogged about it.

It turns out it is not always the case. Last week I was called to help with Innodb crash recovery on box with large amount of memory (64GB) with Innodb Buffer pool configured to be just a bit over 20GB. Innodb recovery was taking long hours with reasonably sized Innodb log files (256M) gradually progressing slower and slower so it was just about 50% after 3 hours with very little disk IO and one CPU 100% busy.

I took oprofile to see what exactly CPU is being spent for and saw the following picture:

samples % app name symbol name
1345161 95.2609 mysqld …