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You need to read Rozhenstein on characteristic functions.

select
sum(case when a < .5 then 1 else 0 end) 'A'
,sum(case when a >= .5 and a < .75 then 1 else 0 end) 'B'
,sum(case when a >= .75 then …

First, let me point out that the Data Cartel ("DBA" means Don't Bother Asking) won't release all the information I requested, so some of this is a guess.

We'll look at a number of dumb-as-a-post SQL techniques. This is proof -- if any were needed -- that bad SQL is worse than …

See Michael Hugos "Think about screens and the data on them to simplify system development " for some helpful insight on what an "application" really is -- access to data. Simple transparency is lifted up as a critical value for software.

I liked the "If you don't believe it could be this …

See Present Perfect for some thoughts on unit testing. See some other commentary on the discipline required to write Python programs in Gnome devs too lazy for python . I think I see the disconnect that makes testing appear to be too costly; I think that some basic "meta-quality attributes" are …

The question seemed simple, which testing framework is the simplest? The situation is complex. There's a web application, there are developers and there are testers. The developers develop, and the testers test. So far, not so complex.

Here's the complexity. The testers are pretty focused on manual point-and-click testing. They …

The Cubulus project and Alexandru Toth 's page describe an "OLAP Aggregation Engine". It is very nice to see advanced work done on the dimensional model.

The cited research dates from 1999 (V. Markl, F. Ramsak, R. Bayer, "Improving OLAP Performance by Multidimensional Hierarchical Clustering", Proceedings of the Intl. Database …

After having written a number of application-specific object-relational mappers, I have been on the prowl for an elegant, enduring solution. I had started to come to grips with Django , and like much of the approach. Django has a tiny infrastructure feature (the settings.py file) which made it unpleasant to …

Actually, the code looks like a clever expansion on my example, in PyCon 2007 (Revised) .

"But wait," you say. "Creating a pivot table in Python?"

Of course. Spreadsheets can create pivot tables from dimensionally normalized data. However, getting the data in this form is often challenging and if there is …

In one form, the question is "How do we handle the [X] transaction in the warehouse?" Another form of the question is "What do we do when [Y] changes?" The third form is less clear, but essentially the same: "How do we maintain [Z] in the warehouse?"

All of these …

I do a fair amount of manual refactoring. I've used WebSphere Studio (Eclipse) to do some automated refactoring, so I have some experience in using IDE's which exploit Java's static type-checking.

However, the question of type checking in a dynamic language is interesting. I don't use a sophisticated IDE for …