One piece of SQL functionality that doesn’t appear to have any consistency or an ANSI SQL Standard is the management of system generated sequential numbers, used for example in suggorate keys.

MySQL uses AUTO_INCREMENT which serves the purposes adequately, however in my documenting of differences with Oracle in my upcoming MySQL Conference presentation “MySQL for Oracle Developers” there a number of key differences with Oracle’s SEQUENCE usage.

MySQL AUTO_INCREMENT to Oracle SEQUENCE Differences

• AUTO_INCREMENT is limited to one column per table
• AUTO_INCREMENT must be assigned to a specific table.column (not allowing multi table use) …

I’ve never used database columns that embedded defined valid values within the schema definition. Within MySQL there are 2 definitions, ENUM and SET. There are a few reasons why, but first an explanation of these data types.

In summary, using the MySQL Sample Database.

CREATE TABLE film (
film_id INT UNSIGNED NOT NULL AUTO_INCREMENT,
...
rating ENUM('G','PG','PG-13','R','NC-17') DEFAULT 'G',
special_features SET('Trailers','Commentaries','Deleted Scenes','Behind the Scenes') DEFAULT NULL,
PRIMARY KEY (film_id)
)ENGINE=InnoDB DEFAULT CHARSET=utf8;


So from this, the following commands allow you to inspect this information via mysql.

…

As part of my next conference presentation Overcoming the Challenges of Establishing Service and Support Channels I’ve been struggling to find with my professional sources, any quality organisations that provide full support for a technology stack, for example a LAMP stack, or a Java Servlet stack.

Restricted to searching via online, I’ve been impressed by what I’ve found at Spike Source www.spikesource.com. An organisation with an experienced CEO, well known in the Java Industry. They certainly have all the buzz words covered in their product information.

Benefits of their SpikeSource Core Stack.

• Fully tested and certified
• Installs in minutes with integrated …

Why oh why would you want to do this. Well it my case, I’ve committed to developing a web application using MySQL 5 features, knowing that I had to upgrade my production server from 4.0

Well as part of doing this, I hit a stumbling block. My current production web server runs RedHat 7.3, and even with all the latest rpm updates, it does not have glib 2.3 which is required for MySQL 5. I’m no guru, but trying to upgrade from Redhat 7.3 to 9, to at least get these rpm is not an easy process. I’m not confident to try to compile glib 2.3 and all it’s dependancies on a production server, nor is it possible to recompile MySQL down (I suspect not). All just too many variables. It appears the time has come to scrap it and work with a more current RedHat Enterprise Linux version. Down side, the 25 web sites are not going to be too happy.

Anyway, as an interim to at least move forward as much as possible I dowgraded the provided …

Did I push to much in my last post? I don’t think so, but I guess it’s a fragile balance sometimes in Open Source between those keen end users, and the developers that do give so much towards their own creations (I understand, I’m in that category myself).

I was very proud of my work yesterday, it took a whole day of my time (I do have better things to do, like finish my own Open Source project HTMLtags, while will allow me to build my sample application, which I can then use for my MySQL Users Conference presentation). I learnt to dig around the net a lot, go on the wild goose chase several times, understand some more under the hoods of compiling, libraries and dependencies in the GTK world I would have otherwise not really cared about. But as I said, I got to a brick wall by the end, and it was dishearting.

It …

One of the great benefits of Open Source, it’s Free, and you can get great support, sometimes even from the developers directly (rather then 5 levels of paid customer support for a commercial product). One of the greatest banes of Open Source, if you have a problem, and nobody has experienced and documented in a forum etc the problem you have with the same OS, libraries etc, you could be totally up the creek without a paddle, boat and for that matter water. (luckily you still have oxgyen)

Well, I’m having this problem with MySQL Workbench. A product promising so much, but if you can’t get the binary working on Linux to even start, where do you go.

You will see via the Forums, I’m not the only person. This is the current …

I’m stuck between a rock and a hard place. I’ve been using DBDesigner 4 from FabForce, an open source visual design tool, and apart from working around a number of bugs, I’ve found it practical to design from scratch. The big plus, it works under Linux.

With the announcement that this was being incorporated into MySQL, called MySQL Workbench, I was looking forward to getting my hands on it. I guess that was about 8 months ago. Finally about 6 weeks ago, Version 1.0.0-alpha was released for Linux. Unfortunately it didn’t work, would not even start for me. Logged as Bug #15421, which got marked as a duplicate of …

Would it not be great if on the MySQL website there was a page of stats (updated daily) that provided statistics like number of installations, a breakdown of versions registered (not certain I like that exact word) , OS’s, countries etc. More specifically, some useful stats on the engine types in practical use, avg number of tables per database etc. Of course the types of stats could be limitless, but with the success of MySQL as well as other open source projects, more imperial figures on installations other then just downloads I think would definitely benefit given the current momentum. (Availability of information to competitors could be both a good and bad thing.) Perhaps figures can be shown in percentages, not actual numbers.

Anyway, nice idea you say, we can all come up with ideas, but how could you implement something like this. …

It wasn’t that long ago that MySQL released the GA Release of Version 5.0 with major new features (Oct 24 2005). It still took 5.0 about a year to go from alpha to GA, however I’d suspect a much shorter turnaround this time.

Version 5.1 is already at alpha, and the largest public functionality mentioned has been Partitioning. It is also anticipated that Storage Engines (a very handy MySQL feature in comparison to other RDBS products), will be a hot-pluggable API instead of a source re-compilation. Now I’ve never even looked at the Storage Engine code, but it’s been talked about a few …

In a recent job interview I was asked the question regarding Unit Testing/Automated Testing of a Database? An interesting question and indeed an interesting problem. I thought it was a good topic to describe what I’ve done in the past, and where I would go for a more complete testing environment given the opportunity of a entire XP project.

This is the approach I have implemented successfully in the past. It’s not a complete solution, however at the time with the client it provided appropriate coverage.

I don’t use a framework such as dbUnit to load data via XML, or specifically test data. XML is ugly to store data, and also with maintenance and comparison. I start with a pre-configured database of representative sample data, refer to my notes later on this, and then I use the tests of the application to perform the necessary data …