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 ...

In-Memory Bitmap Index in Postgres

I have written twice already that bitmap indexes are not implemented in Postgres. But somebody may as why then explain writes that it used Bitmap Index Scan? However, that is not on-disk index I wrote about. One of the most interesting analysis of performance I found is at Depesz.com, which is a blog of a Polish database ...

FiFO with SQL

I am going to create small system/website that will allow me to manage my stocks, and monitor the portfolio. I do not have much of it, but I cannot access the data from wherever I want and it is not so dynamic. Beside the design itself I came across a problem of recreating a FIFO ...

PGOpenCL – PostgreSQL and GPU

I wanted to play a bit with PostgreSQL and CUDA, but to make it work it would be worth to have both PostgreSQL and sample CUDA program compiled. There are many sources online about integrating PostgreSQL with CUDA, but most of them use outdated CUDA features and are copies one of another. Probably it is ...

BigData (R)evolution

I want to learn some more about the scale, but not scale in general but scaling data storing and processing. Nowadays if you hear about the big data, it often implies hadoop based distributed system. As Yahoo is one of the biggest contributors to Hadoop at the moment, the best tutorial is also on their ...

PostgreSQL 9.3

I did not realize that on my brithday PostgreSQL hit 9.3 mark (see a news). With this release there is a new join type that I first hear about. It is named LATERAL JOIN. There is no need for me to copy the documentation, so if you want to know what that is head to ...

SAS E-mail alert

When you have a long code to run you may not want to just sit and wait, maybe have a walk around and be notified when the code finishes to execute? That is possibe if you have a phone that you can check your mail on and your SAS server is configured to send e-mails. ...

B-tree or Bitmap

Recently I read a lot about databases, mostly theory but also from the design point of view. I have to admit that until recently I had no idea what a B-tree is. I mean beside that it is a kind of a data structure, but how it is build and why on average there is ...

No Duplicates in Subset

Yesterday I was helping a friend of mine with an interesting problem. There is a big table ~4MLN rows, it is wide (has many columns, lets say 30). We are interested in getting rows, which contain duplicates in 5 columns, we do not care what data are in other columns, at least not with regard ...

Adding DSN with VBA

Access is a popular choice for a database GUI. There is no need to know how to connect with a specific database from Access as long as we know how to use an ODBC connection. To make everything fully automated it is even possible to add such a connection with a simple VBA script, maybe ...

Shortcuts in Excel

Knowing Excel shortcuts is one of the features that can save you hours every week, provided you use Excel a lot. Beside very typical and well known like CTRL+C and CTRL+V there are dozens of other. There is no other way to remember all of them than practising. At my previous work I was amazed ...

Paste Faster into Excel

Excel and Access often do come along. When you have make them work combining one database with dozens of Excel sheets it is necessary to be able to read and write data fast, otherwise it becomes annoying pretty fast. There are several ways to apporach this problem. Reading Excel sheet into Access can be easily ...

Fill To The Next

Fill To The Next
Pivot tables are very useful, but later on it might get really boring filling the missing cells in the first columns. For example given a table like the one in the picture below