ICDM 2006 will be held in Hong Kong.

The 2006 IEEE International Conference on Data Mining (ICDM-06) provides a premier forum for the dissemination of innovative, practical development experiences as well as original research results in data mining, spanning applications, algorithms, software and systems. The conference draws researchers and application developers from a wide range of data mining related areas such as statistics, machine learning, pattern recognition, databases and data warehousing, data visualization, knowledge-based systems and high performance computing.

KDD 2006 will be held in Philadelphia.

During the past years, the ACM SIGKDD conference has established itself as the premier international conference on knowledge discovery and data mining with an attendance of 600-900 people.

From Nov. 26th to Dec. 1st 2005, I’m be in Houston for ICDM’05 where I’ll present our paper An Optimal Linear Time Algorithm for Quasi-Monotonic Segmentation. For a limited time, my slides are available on the Web.

(If you are a thief, I’ve got two sons guarding my house, so don’t bother.)

I thought I had written a piece about this, but no. So, there you go. Tabs are evil in text files. Why? Because the tab character (\t) has vaguely defined semantics. It means “insert x spaces” where x depends on the text editor and the preferences of the user.

For example, the following two lines of code will appear perfectly aligned to me, because I prefer short indentations (only 2 characters):

[space][space]print “dog”
[tab]print “cat”

But if someone types the following code

[space][space][space][space]print “dog”
[tab]print “cat”

then it won’t look aligned at all for me.

The solution? Tell your text editor to dynamically replace tabs by spaces. For vim, you can achieve this by putting the line “set expandtab” in your file “~\.vimrc” or by typing “:set expandtab” while vim is running. The equivalent should be possible with all good text editors.

Now, go do it. Configure you text editor properly.

Disclaimer: There is one case where this brings your trouble. Makefiles, for some odd reasons, require actual tabs. But I write a lot more code than makefiles and so should you.

It looks like JOLAP is dead. The final specification has been approved on June 15^th 2004. However, to this day, except for Mondrian and Xelopes, I know of no implementation of JOLAP. According this this thread, Oracle has no intention of ever supporting JOLAP.

On the other hand, Oracle doesn’t support nor does it plan to support MDX or derived technologies such as XML for Analysis (XMLA) and more recent specifications. But, you can get MDX support in Mondrian and in SQL Server standard edition or better. I am pretty sure IBM supports MDX and maybe XMLA, but with recent changes in their OLAP product line, I must admit I’m a bit confused.

This leaves us with no cross-platform OLAP query standard. After all these failed attempts, it is very depressing.

Update: Daniel Guerrero from Ideasoft correctly pointed out to be that the current JOLAP spec. has not been published yet as a Final Release, but only as a Final Draft. The Final Draft has been approved in June 2004 (though IBM abstained), and normally, the Final Draft ought to be a Final Release by now, but this didn’t happen. The difference is significant because, right now, the JOLAP license, granted by Hyperion, is for evaluation purposes only. This means you can’t go out and implement JOLAP without risking legal troubles. We can imagine many scenarios on what is happening, but I’ll vote for an Intellectual Property issue.

Oracle has recently made available their Oracle Database 10g Express Edition. Its limitations are that it can only run servers with one processor, with 4GB of disk space and 1GB of memory. It is not sufficient for even a small data warehousing project, but it is great for teaching a class. It is available for Linux and Windows.

Microsoft recently made available for free its SQL Server 2005 Express Edition. Obviously only available under Windows. It lacks enterprise features, it is limited to one CPU, 1GB of memory and 4GB of disk space: basically the same limitations as the Oracle Database 10g Express Edition.

IBM is thinking about doing the same with DB2. Currently, it offers the free Java-based Cloudscape database running on any standard Java Virtual Machine (JVM). They also offer a free PHP-bound version of DB2 called Zend Core available for Linux and AIX, and to be available for Windows.

However, it is not like you are limited to what IBM, Oracle and Microsoft have to offer or have to accept the limitations of their “free” products. There are many good free and open source databases such as MySQL, PostgreSQL, MaxDB, Firebird or Ingres. None of these free alternatives is as powerful as an Oracle database, but if you compare what you can buy with zero dollars, the big guys don’t necessarily come on top.