Courses in Databases

I was preparing a post about what can slow down a query, but when I was reading a lot of different stuff online to make sure I am writing truth I encountered several interesting papers, and presentations that I think are worth reading. First of them is a series of presentations regarding Data Processing on ...

Know your database – a complex query

I have seen in my life many people learning SQL without prior understanding how databases work. But there are many crucial things that can make writing queries more fun, if it is not fun enough. Optimization in terms of memory use and execution is one of them. I would even say that is the most ...

Concatenate Array

Concatenate Array
Yesterday I made a post about concatenating range with strings in Excel. But there is one problem, it does not work with array formulas. So you cannot put condition on one column and based on that concatenate values form another. For this you would need a function like the one below. And a sample use.

Concatenate Range 1

Concatenate Range
The Excel’s concatenate formula, or operator & do not work with ranges. You have to specify each parameter you want to add to the string. Sometimes it may get annoying, especially when the range is dynamic and depends on some parameters. Then it would be useful to have a formula that can work with ranges, ...

Rank with Exclusion

Rank with Exclusion
Recently I stumbled upon a problem of ranking observations with exclusion, i.e., not including all of them in the rank. In Excel prior to 2010 you would normally use function =RANK(), in all later versions there are also functions =RANK.EQ() and =RANK.AVG(). They differ only in a way of assigning a rank to observations which ...

DebugName for SharpDX.Toolkit.Buffer

DebugName for SharpDX.Toolkit.Buffer
I am still learning a lot about building DirectX based applications, and I am using Visual Studio Graphics Debugger more extensively. But when your program grows to much it may get kind of hard to track all your resources. There is a nice feature of DirectX that helps you with that, it is a possibility ...

SharpDX.Toolkit Constant Buffer

SharpDX.Toolkit Constant Buffer
You should not expect a lot of documentation on ShaprDX. You may argue that it does not need it as it is a wrapper around DirectX so everything could be found on MSDN. That is true, as long as you use pure DirectX. I wanted to make some use of the SharpDX.Toolkit, and that is ...

Picking a Laptop

I was wondering about buying a new laptop but having some issues with my previous choice I decided to do a bit mode in depth investigation. Currently I own Lenovo ThinkPad T410 (type: 2518 Q6G). I bought it some time ago because display of my Thinkpad T41p broke down and I needed a laptop urgently. Most ...