Note to those of you that have written me with words of appreciation and encouragement as well as suggestions for new pop quizzes: First: Thanks for the kind words! Second: If you’re awaiting an answer, please rest assured that I do read your mail! I get mails relating to the pop quizzes daily, so I’m having to work on this in batch mode. You will get an answer from me in a few days.

Today’s question comes from Bertrand Gorge, who tells me he uses this as a test question during interviews. So if you’re looking to work for him, make sure you’ve understood this!

The following two queries do not return the same result. Why ?

SELECT table1.*
FROM table1 LEFT JOIN table2
ON table2.table1_id = table1.id AND table2.val < 5

SELECT table1.*
FROM table1 LEFT JOIN table2
ON table2.table1_id = table1.id WHERE table2.val …

JavaScript? Check. Ajax? Check. “Beta” tag? Check. Bright colors? Check. Big fonts? Check. Rounded corners? Check*.

In a fit of “someone really ought to have made such a tool already” and wanting to play a bit with Javascript and DOM, I humbly present my Web 2.0 - compliant MySQL DATE_FORMAT() and PHP DATE() tool.

Not very fancy or anything, but it should go some way toward saving you the effort of looking up formatting codes and running your scripts for the nth time to check whether things work or not.

Any and all suggestions for improvements are appreciated!

Virtual Hosting Howto With Virtualmin On CentOS 5.1

This tutorial shows how to set up a CentOS 5.x server to offer all services needed by virtual web hosters. These include web hosting, smtp server with (SMTP-AUTH and TLS, SPF, DKIM, Domainkeys), DNS, FTP, MySQL, POP3/IMAP, Firewall, Webalizer for stats.

This poll did not get a lot of voters but I thought I would post the results to show you the priority of the individuals that did vote. Poll: What is your highest priority with MySQL?Performance Tuning  20% Backup and Recovery 20% Monitoring and Management 16 % High Availability 16% Scalability 12% Storage 10% BI and Reporting 3% Business Strategy 3%

Virtual Hosting Howto With Virtualmin On CentOS 5.1

This tutorial shows how to set up a CentOS 5.x server to offer all services needed by virtual web hosters. These include web hosting, smtp server with (SMTP-AUTH and TLS, SPF, DKIM, Domainkeys), DNS, FTP, MySQL, POP3/IMAP, Firewall, Webalizer for stats.

MySQL configurations cover the range from developers installing a simple MySQL database for a LAMP application to the largest Internet companies using MySQL to deliver web content.There are two different profiles that cover this range for installing,  configuring and managing MySQL database servers:Profile 1: Individuals or small organizations that wants to use MySQL to create a simple database

Since well before I joined MySQL in 2001, I have had contact with now-members of the four-headed management team of Germany’s top-notch PHP experts and solution providers Mayflower GmbH.

Mayflowers and MySQLers frequently pop into each other at PHP conferences and other Open Source events, and meet informally under various circumstances ranging from Christmas parties to Biergarten discussions. It’s always interesting to exchange thoughts on virtual companies, Open Source, business models, IRC, scrum, and finding developers (some of which have worked for both MySQL and Mayflower, incidentally). And by sheer coincidence, Mayflower’s Munich headquarters is now about 150 metres from where I live, in the same street that I look out at from my home office (Mannhardtstr.). This time, they copied us, though — I …

Next Thursday 6 March 2008 at 17:00-18:00 CET, there will be a panel on “The Commercialisation of Open Source” at the Future Talk Booth in Hall 9 (Stand A30) of the CeBIT fair in Hannover, Germany. One of the purposes of the panel is to publish the Open Source Yearbook 2008, the fifth in a series of yearbooks produced by a team around Professor Lutterbeck of the Technical University of Berlin.

I’ll be one of the panelists, representing MySQL AB. Other panelists are from OpenOffice.org, Citrix, the Zope user group, and the Free Software Foundation.

For the book, I wrote a chapter called “ …

Today we were doing some basic scaling exercises on some code, which resulted in several million extra rows in one of our tables in one of the development environments. Rather than refresh the data, we decided just to prune those new records and reset the auto-increment value. Imagine my surprise when executing the following code hadn’t [...]

The World Tour starts on IRC next week!

The schedule is as follows:

• Wed 5 March 2008: Ian Murdock, 7am PT/16 CET. Ian is the ian of Debian and Chief OS Platform Strategist at Sun Microsystems. Wikipedia puts it like this:
  

  Since joining Sun, he has led Project Indiana, which he describes as “taking the lesson that Linux has brought to the operating system and providing that for Solaris,” making a full OpenSolaris distribution with GNOME and userland tools from GNU plus a network-based package management system.

• Thu 6 March 2008: Simon Phipps 6am PT/15CET. Simon is Chief Open Source Officer at Sun Microsystems. …