I’ve bought plane tickets to the upcoming MySQL Camp in November. This is looking like a very fun time, with lots of community members, MySQL employees, and Google developers attending. It’s an “un-conference,” which means there is no set schedule, and it’s up to us to make out of the event whatever we wish it to be. If you’ve been reading my articles or using my tools, is there anything you’d like me to present on?

This key should give you a guide how to best tune you MySQL database systematically... It should also work similar for other RDBMS.

Maybe not breaking news, but I think it’s interesting enough of a point, and I didn’t really find anything about the topic when I googled it. If you do any addition, subtraction, multiplication, or division (and probably a lot more mathematical functions for that matter) and NULL is one of your values, the entire expression will evaluate to NULL.

For example, this statement returns NULL:

select 4 + NULL;

+———-+
| 4 + NULL |
+———-+
| NULL |
+———-+

Normally you wouldn’t do the above in such a simple way, for instance, you might do some addition in a subquery. For example,

select 4 + (select val from table1 WHERE id < 3 LIMIT 1);

+---------------------------------------------------+
| 4 + (select val from table1 WHERE id < 3 LIMIT 1) |
+---------------------------------------------------+
| NULL |
…

Dana Blankenhorn of ZDNet has an interesting interview with Darryl Dewan of VA Software. In the course of the interview, Dana queries Darryl as to whether open source businesses can deliver serious financial heft. The answer?:

Maybe the good old days really are gone for good. But is open source to blame for that? No more, I think, than the end of the gold rush can be blamed on mine automation.

There are still fortunes to be made, Dewan said. Look at the money the founders of MySpace made, or those of YouTube will make, and all the gazillion Google-aires.

"You can create things online and do things online and you don't need to program," Dewan concluded. This is not a bad thing. Unless you want to become a millionaire through programming.

I disagree (with all due respect to Dana, to whom much respect is due). Marten Mickos …

Red Hat this week announced their application stack which includes JBoss, Hibernate and support for MySQL and Postgres open source databases.  Given Red Hat's recent acquisition of JBoss, the announcement was not a surprise, but it's still good to see that they are making progress moving up the stack and providing greater ease-of-use and integration. 

Red Hat remains the number one vendor of Linux and this move shows that Red Hat could be the "market maker" for open source stacks.  They are definitely raising the bar on competitors and that's good news for customers.  Red Hat will now be distributing certified binaries for MySQL as part of this stack and is also providing front line support backed up by our own support organization for complex issues.  Red Hat is offering multiple levels of subscription support for the stack, starting at …

Web applications can easily become very complex. Several hundreds of thousands of lines of code (no HTML templates!) is usual at larger corporate solutions. This also means that your PHP applications follows the standards like object oriented programming, nested classes etc.

When it comes down to detect security vulnerabilities, a lot of tools are available. In a previous post I told you that we developed Chorizo! mainly because we needed a tool that checks for security vulnerabilities (both XSS issues and server side issues) very easily. I think our GUI is very nice :-)

In a previous post I introduced Morcilla to you (see video here and here and …

Today I have some good news to announce! Finally, after quite some struggles and some disappointments because of 'optimistic planning', I can tell you that the first version is working.

It is a testing version which has the following functionality:
- An example sensor publishes random values on the bus;
- A insertion interface reads all sensor data on the bus (it is ready to receive data from multiple sensors) and writes it to the database. It creates tables for every new sensor;
- A selection interface listens to SQL requests and creates data sources which publish data on the bus at a specified interval;
- An example client publishes it's request on the bus and after receiving a data source ID, subscribes to this data source. It will from thereon receive the result periodically.

I will add some logging to the code now so I can extract some meaningful performance information.

…

At this point most of the code is in place for Connector/ODBC v5 Beta 1 so the emphasis is on getting all of the Post-Build Tests to pass.

Apparently all of Google's developers suck:

Despite attempts at education, our developers regularly write loops that retry indefinitely when a file is not present, or poll a file by opening it and closing it repeatedly when one might expect they would open the file just once.

Developers rarely consider availability. We find that our developers rarely think about failure probabilities.

Developers also fail to appreciate the difference between a service being up, and that service being available to their applications.

Unfortunately, many developers chose to crash their applications on receiving [a failover] event, thus decreasing the availability of their systems substantially.

A word of advice... Just make your hiring practices more rigid. Google is apparently at 10 interviews now. Just make it 20 …

It seems like just days ago we were wrapping up the 2006 MySQL Conference and now we've got another one in the works.  Next year's conference is once again jointly put on by MySQL and O'Reilly and we've got the Call For Papers open until November 6.  Having helped organize many conferences in the past, I know that many (most?) potential speakers wait until the last minute to submit their talks.   However, your odds of being accepted are actually higher if you submit your talk earlier since conference organizers try to lock in some of the talks early.   The most popular topics are those that show "best practices" of using MySQL in real world scale-out applications.  Additionally, topics on performance tuning, clustering, partitioning and database management are always welcome. 

The conference will be held in Santa …