Giuseppe Maxia teased me last week to see whether I could decipher the notice on the Italian web site Punto Informatico about “MySQL University, lezione gratuita su Lua“.

It’s about Giuseppe teaching MySQL University attendees (for free as in both beer and speech) on the Lua scripting language. The MySQL reason to learn Lua is to do scripting in MySQL Proxy. Don’t worry, the MySQL University session is in English, not Italian, and Giuseppe has deciphered the Italian himself in his blog.

You can attend MySQL University virtually with slides in PDF and Wiki, audio …

A while ago, I had a discussion with Stewart Smith, Vinay Joosery, Monty Taylor and a number of other MySQLers who know much more about MySQL Cluster than I do. The result is a model for using MySQL Proxy to offload MySQL Cluster from doing Table Scans, without touching the application.

The discussion started from me asking Stewart about the largest road block for expanding the number of use cases for MySQL Cluster. “Oh, that would probably be doing JOINs and other SELECTs requiring the scanning of large parts of the database”, he replied. “There, other storage engines are faster, such as MyISAM and InnoDB.”

In a very simple view, the application talks SQL with MySQL Cluster, and gets responses.

Stewart’s insight can be refined into the first simplistic diagram by adding the recognition that “SQL” can consist of

1. UPDATE, INSERT, DELETE statements (very light, usually …

One of the first things I did when I started learning MySQL is to find a decent GUI tool to administer the server, since I didn't think that the bundled MySQL Query Browser/MySQL Administrator is what most people use for complex work. Luckily, I was right.
There is a huge variety of MySQL development tools - some better and some worse. I'd prefer if I only had one tool that does it all - but if that's impossible, the important thing now is to pick the right one for the job.
Here it is, the (nearly) complete list of 3rd party tools. It took me a while to find out about all of them - so I hope this saves people quite some time there.
Here are the best ones I use on a regular basis, each one is good for different set of tasks:

• SQLyog by Webyog (commercial, with free community version)
  Best combination …

Followers of the Forum Nokia Developer Discussion Boards saw interesting pre-announcements last month:

Nokia has ported MySQL and PHP to Symbian.

With 165 million cumulative Symbian smartphones shipped since the formation of Symbian and currently 134 Symbian smartphone models commercially available, it would be interesting to see the effects on the 8,134 third-party Symbian applications commercially available by what Nokia calls “PAMP”.

Availability is planned for next month, at the CCNC 2008 (Fifth IEEE Consumer Communications &Networking Conference, 10 - 12 January 2008 in Las Vegas, Nevada).

Johan Wikman of Nokia, who …

When I received and email almost two years ago about a announcement that MySQL was going to release and enterprise product I was very excited. I was looking forward to a redhat style model of vetting releases in the community then offering a proven stable version to paying customers. I saw it as a great way to for MySQL to generate revenue as well as eliminate the need for people to stay a few releases back from the head and guess when to upgrade.

The release shocked me. What was originally emailed to me and the final plan were two very different things. It was a plan to hand paying customers bleeding edge code that had been tested only by MySQL’s QA team. It seems MySQL has forgotten the years of testing by millions of community members that has given MySQL the stability we have grown to trust. I predicted the instability of MySQL enterprise back in October ‘06 by saying that releasing patches in enterprise that hadn’t been tested by …

We are hitting a few walls with a CouchDB deployment and both Damien and I are a bit puzzled. This posting tries to attract someone with a clue to help us out. Our problems might result from not understanding the documentation correctly, but with evidently inaccurate material, we stand little chance. Here it goes.

Spidermonkey hogs memory

Or its garbage collection is a little ineffective. CouchDB uses Spidermonkey, Mozilla’s Javascript engine to create views on its databases. The user provides a Javascript function and CouchDB uses Spidermonkey to determine which documents to include in a View. The Javascript script that evaluates and executes the user’s function runs as a daemon.

We have a global variable there, map_results (declaration in line 19) that gets reset to {} for each document and map …

I heard someone said that if you do not need to know the intrinsic details of the database, then go for Oracle. I love Oracle because of its robustness. No database can compare against it. It has been there for a long time... Some other database that rose together with Oracle have already died down, but this database still lives.

Am I going to compare MySQL and Oracle here? Nope. For all you know, you really did not have a choice as to which database you have to choose. Your boss chose it for you. So, what is the point of having a title called 'Oracle vs. MySQL' if I'm not going to compare them? Nothing really. It's just a point where there are certain things in life that you really don't have control about.

If you enable logging of all queries as "slow queries" using the patch or MySQL 5.1 you can get log file to grow huge. Same may happen with general log file. In some cases we've got log file sizes of 100G or more which may need to be cleaned up.

Here is some danger waiting for you at least on typical Linux systems - If you follow most simple process - delete log file you do not need and run "FLUSH LOGS" so file is recreated and space reclaimed you can get into serious trouble. File close operation will when perform deletion which can be quite a long process, depending on filesystem and log file size - we've seen it to take 10 minutes or more in some cases. When log file is reopened MySQL will be practically unavailable causing unanticipated downtime.

The workaround for this problem is very simple - instead of deleting …

The review of my first six months of service with (mt) Media Temple is posted at Web Hosting Talk.

I was looking for a function in the MySQL documentation on how to get the first day of the month and I couldn't find one. Although I found that there was a LAST_DAY function. So, here's my function to get the first day of the month.

select DATE_ADD(LAST_DAY(DATE_SUB(CURDATE(), interval 30 day), interval 1 day);

This is how I computed the first day of the month. I'm not sure if there is a simpler way of doing this.