instantOLAP: The ROWNUM() function and grouping

InstantOLAP is a lightweight reporting and OLAP system. It’s made for OLAP reports. But if we have a non-aggregating query, we can still list all the rows by using the ROWNUM() function, which helps iterating over the result set. But we’re not able to use a dimension for grouping the rows of the result set.

I’ll give an example: imagine we have rows describing some customers. Each customer is in exactly one customer category. What we now want to have is a list of all these customers, but grouped by customer category. And because we have a dimension for the customer category, we want a separate table for each category. The naive solution seems to put the customer category dimension as an iteration into the outer block of the pivot table. But this will not work because ROWNUM() – an thereby the LINE_DIMENSION – is the only dimension used for iteration.

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The Google Chrome phenomenon

I have heard of Google Chrome for the first time on September 1st. A comic strip about Chrome was leaked on the Internet. At that time, there was no software download available. Rumors soon followed about the early availability of a beta version and a Google press conference the next day. This press conference actually took place and the software was then available for download in a beta version.

In the tech-oriented area of the internet, Google Chrome caused more heavy waves than any comparable event before. Reports and discussions surfaced everywhere. According to one source, Google Chrome already had a market share of over 1% after only a few hours – probably caused by curiosity like mine.

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Enough Talend for the job?

I’m part of a team that builds a data warehouse for our client, an international recognized car and motorcycle manufacturer. Right now, the data comes from various sources, most of it is provided in CSV files. As a first step, these files are loaded into a staging area. It has been decided to accomplish this task with the help of an ETL tool. The tool that has been selected is Talend Open Studio (TOS).

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Wicket first contact

While working on an AJAX web application a couple of weeks ago, a co-worker asked me what I know about Wicket. Not much at that time. I knew it was some kind of component based web framework, but only in the sense like everybody knows that Porsche is a German car brand.

During the recent holidays I spent the entire time away from work and with my family. As most of the time when I’m away from work I made a list of things to look at. Wicket was not on that list. I seldom make it at least half way thru that list anyway. It was the same this time. But then I saw this article on TheServerSide about the release of Wicket 1.3. The big amount of comments caught my interest. Suddenly, Wicket was on that list.

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Why I upgraded to GWT 1.4.61

The previous version GWT 1.4.60 came out on August 27th, 2007. A couple of days later I had upgraded all my applications, the expression calculator demo too. None of the applications suffered from a strange bug except the demo. It appeared only when Microsoft’s Internet Explorer was used. A message box was displayed that told the user: “operation aborted”. The page wasn’t shown at all, the user only saw a blank page. I had to remove the demo, at least from the home page. Since only the demo was affected, I didn’t go back to GWT 1.4.59.

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