Transpose in Oracle
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Transposing data means changing data from a row into a column. Starting from version 11, this is possible in Oracle as well. It is possible to translate some values that…
Reading and writing in Java
Reading and writing from and to files is not easy in Java. This can already be seen if one simply googles on “Java Filereader problem”. This generated 477000 hits. Apparently,…
Another set of keys and values
Another example on how mapper and reducers are used in a Hadoop context is given below. This programme is created as three classes. One class is an overall class that…
Map and reduce – what happens?
In Big Data, the concept of mapping and reducing plays a huge role. The idea is that a a massive dataset is split over several servers. On each server, a…
Hive – connecting from SQL Developer
In my impression, the big development that takes place now in the world of Big Data is the creation of connectors. Such connectors enable us to continue using standard tools…
R – the shortest name possible
For some reason, short names are popular as computer languages. Think of “C”. Another example is “R”. R reminds me a bit of Matlab; it is an easy to learn…
Hive, SQL on Hadoop
In a previous post, I discussed the difficulty to use Hadoop with its Big Data structure. One must write two different Java programmes. One programme is a so-called mapping programme;…
Pig: yet another approach to handling big data
In another post, I discussed how Java can be used to analyse data in a Big Data environment. The problem then lies with Java itsself. Java is not a tool…
Python: another language to access Big Data
In an earlier post, I showed how Java could be used to access Big Data. I also stated that I had many problems with Java itsself. I noted that I…
Hadoop: my first java programme
Today, I created a Java programme to get myself acquainted with the usage of Hadoop. I took an existing java programme to start with. This existing programme can be found…