The work on subquery optimizations goes on, and we're already curious how the assortment of new 6.0 subquery optimizations compares to what is found in other DBMSes. MySQL's new strategies are not DBMS theory breakthroughs, similar ideas have been implemented in other DBMSes, but when you take this list of strategies and put them into this kind of optimizer, the result has no direct equivalents in any other DBMS (or at least we believe so).

The first thing we did was to take a look at PostgreSQL as it is easily available and seems to have at least decent subquery handling (or even better than decent, I have not heard much complaints). And the first interesting difference was handling of correlated subqueries. With exception of materialization, MySQL's new subquery strategies do not care if the subquery is correlated or not.

For example, …

While working with a client we found a query that can crash MySQL. It has to do with ref_or_null outer joins where the table contains a null value. MySQL fails to tell the storage engine to initialize the index before reading from it. It crashes when used with MyISAM tables but it could result in an incorrect key file for table error with other storage engines. You can find the test case and patch in bug #34945. I’ve waited to blog about it until MySQL approved my patch. As of this writing my patch has been approved and committed for release in 5.0.60.

Apache is a fairly straight forward setup if you use some utility or distribution to help you. A manual installation will take more time. You can Google installation instructions or use a utility like XAMPP to simplify the installation. XAMPP is a distribution that will walk you through an Apache, MySQL, PHP, phpMyAdmin installation. Once you get comfortable with XAMPP these software

The Conference Speakers of the 2008 MySQL Conference provides some common and interesting names of companies not common in MySQL circles such as eBay, Microsoft Corporation, HP, Symantec. I see speakers outside of MySQL from countries including USA, Canada, Brazil, Germany, Japan and Australia.

I did some data analysis of the speakers list. There are 150 speakers, there are 45 from MySQL. Other companies with multiple speakers include Sun Microsystems, Kickfire, Linbit, Cafepress, Open Query, Proven Scaling, Standford Linear Accelerate Center, UC Berkeley, Siz Apart, The Hive, Zmanda, MySQL Performance Blog, Infobright, Digg, Grazr and of course PrimeBase Technologies.

Only two MySQL speakers have listed “MySQL/Sun” the rest are “MySQL”. I wonder what the policy is here? You have “Oracle / Innobase” and “Innobase / Oracle Corp.” …

Following A day with Jan Kneschke - Architect of MySQL Proxy, today I’m with Michael Zinner in Vienna, Austria. Michael is Team Lead of the MySQL GUI tools team at MySQL.

I met Michael two years ago the 2006 MySQL Users Conference. We had communicated prior to that and I’d even used his very successful DB Designer a number of years prior to this. The present project of the GUI team is the MySQL Workbench which is a beta release.

Again, I find a key MySQL developer using a Mac, this time as …

I’ve been accepted to speak at the upcoming 2008 OSCON Conference in Portland Oregon July 21-25 2008, where I’ll be speaking with Giuseppe Maxia on MySQL Proxy. I haven’t seen a schedule yet, so I’m interested if there are any other presenters on MySQL topics!

During the last month, I have had the opportunity to be involved in three MySQL training classes that have included Sun employees. Without exception, every Sun employee has shown a lot of enthusiasm about the potential for MySQL and Sun. Every Sun employee has gone out of their way to welcome MySQL employees. There have been a lot of excellent discussions on the potential of Sun and MySQL

I have an issue I hope someone can help me with. I am generating RRDtool graphs (for Cacti monitoring templates for MySQL, which I’ll release soon) that have up to 11 different metrics on them. With that many lines or areas on a graph, it becomes very hard to pick colors that are easy to see and easy to distinguish from each other. What’s a good way to choose such colors? Is there a way to do it automatically — is there a formal method that will produce good results?

I know some color theory and I have read about how you can distinguish colors from each other (hue, value etc). But I am unsure the best way to choose this many colors. Trying by hand produces garish results or graphs that are just hard to read.

My first attempt to solve this with a program was to simply create …

When people think of MySQL they normally think of MySQL running across multiple Intel servers running Red Hat, SuSE or Windows. This is great for small and medium sized organizations. However, adding a number of Intel boxes and dealing with heating, electricity, power and storage is not an ideal scenario for larger organizations.

As MySQL grows in popularity, I believe more organizations are