The latest from the MySQL community

The table t is defined thus:

  CREATE TABLE t (
   id INT NOT NULL,
   data CHAR(30) DEFAULT NULL,
   UNIQUE (id, data)
  );

You now do…

  INSERT INTO t VALUES (1, NULL);

Which causes one row to be inserted into the table. Keeping in mind that the UNIQUE index spans across both columns, what would happen if you were to repeat the INSERT command?
Spanish translation by Marcos Besteiro
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Since 2005, every year we have done some kind of "Mayflower weekend". As we're a bit of a distributed company (departments in Munich and Würzburg, called Herbipolis, several "on-site departments" at some of our biggest customers, an offshore department in beautiful Argentinia and since 2007 a sister company called SektionEins located at Cologne watching out for Web Security) it's always fun packing the crowd together and putting them into a hotel somewhere in Germany (or Barcelona, Spain in 2006 and Budapest, Hungary in 2007). If you followed Wolfram's blog you noticed that we also had some external guests (if you need a Dojo freelancer, I recommend hiring Wolfram although he's a Pythoneer ;-) ) alongside the camp. The event was located at the hotel …

One of the workshops on our Barcamp two weeks ago had to do with the MySQL-Proxy from Jan Kneschke.

Yet, we found out, that the proxy is rather unuseable for our task. Read here why.

Continue reading "Playing arround with the MySQL-Proxy on Mayflower-barcamp"

I’ve been giving presentations at work each week about MySQL DBA topics. An hour of speaking about the things one does on a daily basis is rather fun, and hopefully spreads the work about how efficient MySQL is to administer and setup, as well as optimize and troubleshoot vs MSSQL and Oracle - for which we also have weekly classes.

Recently I’ve been covering backup and recovery methods, which brings me to my next point - the talkback scripts I have been integrating into my Monolith application. These scripts are wrappers for mysqldump that do extensive error checking for file completion, directory pruning to rotate out old backups per the backup retention period policy, and then report back via email and to a separate database for tracking purposes.

Here is the create table for the reporting aspect. Note: this is part of the Monolith 1.2 release which is still in beta. Stay tuned for the release that includes this, as well as …

***All point news bulletin***Do not ever use NOW() - `datetime field`! Broadcast this from the mountaintops of open source to the valleys of companies who dabble in it.Instead, use the following:TIME_TO_SEC(TIMEDIFF(Now(),`datetime field`))There are other ways to do the above, just as long as you do not use NOW() - `datetime field`.Wanna see proof?mysql> SELECT RIGHT(NOW(),8) `Now`, RIGHT(

Someone asked me what applications were good/bad for MySQL Cluster. As I’ve now actually had experience with a Cluster setup and a real-life application of it, and dug through the manual, I present a few characteristics of applications that will work with Cluster, and why they are so (so that if you have an [...]

With MySQL 5.1 reaching release candidate stage, I have been reviewing ALL of the MySQL Certification exam questions to hunt down any items that may now have been superseded by the march of progress. And right now the Merge Storage Engine has caught my eye.

With 5.1 comes the ability to disable the Merge Storage Engine. It used to be that you could not disable the MyIsam, Memory, or Merge engines. They were compiled in and could not be disabled. They were a constant, solid and dependable. But now you can pass --skip-merge to mysqld and disable it.

Does this option effect a lot of people? I honestly don't know. But it will change a few questions on the certification exams. And it may make a great piece of knowledge if they ever publish the Trivial Pursuit MySQL Edition.

On my InfoWorld blog I've posted an interview with Olli Toivainen, Nokia's director of product management.  He's one of the unsung heroes behind the N Series of Linux-based Internet Tablets.  Although I couldn't get him to make any new announcements of future products, he does give quite a bit of good info around the N810 Internet tablet, which I think is one of the coolest devices out there.

For those interested in music, I've also posted an interview with Joe Trohman …

The PHP manual basically tells you not to use Apache 2 with a threaded MPM and PHP as an Apache module. In general, it may be good advice. But, at dealnews.com, we have found it very valuable.

Apache threaded MPMs

Well, first, what is an MPM? It stands for Multi-Processing Module. It is the process model that Apache uses for its children process. Each request that comes in is handed to a child. Apache 1 used only one model for this, the prefork model. That uses one process per Apache child. The most commonly used threaded MPM is the Worker MPM. In this MPM, you have several processes that run multiple threads within it. This is the one I will be talking about. You can read more on Apache MPMs at the …

With the acquisition of MySQL I expect that many people might end up comparing MySQL and PostgreSQL using sysbench. It is like a micro-benchmark utility which includes an oltp mode which is used quite a bit to show MySQL performance. It can actually also be used with PostgreSQL. So this post is about how to configure sysbench to work with PostgreSQL. (Primarily a note for myself since I had to do hunt around to get it configured for PostgreSQL).

 
First download the latest version of sysbench. I had downloaded the version sysbench-0.4.8. After gunzip/untar I had to to figure out few steps to get the right configure script for it.

I am going to use the Sun Studio Compiler (since PostgreSQL in my case is also built with Sun Studio Compiler). So I will need the compiler cc in my …