Category Archives: data warehousing

ElasticSearch: Restful services

As we have seen in a previous post, we communicate with the ElasticSearch server via messages that are sent to a server. On the other hand, the server responds in messages that are received by the client. This system of messages are labelled as s “RESTful” structure. This RESTful structure is based om messages that… Read More »

Scala and RDDs

RDDs are the basic unit in Scala on Spark. The abbreviation stands for Resilient Distributed Dataset, This shows that we are talking on full data sets that are stored persistently on a distributed network. So the unit of work is comparable to a table. We have two different operations on this RDD. These are a… Read More »

A python script with many steps

Pyspark is the python language that is applied to spark. It therefore allows a wonderful merge between spark with its possibilities to circumvent the limitation that are set by the mapreduce framework and python that is relatively simple. In the scheme below, some steps are shown that might be used. sc.textFile allow to read a… Read More »

Dataflow in Oracle Warehouse Builder

I know that Oracle Warehouse Builder (OWB) is at end of life. On the other hand, I encounter OWB quite often and it is interesting to see how it works. So investigate how it works, I created a dataflow. It it a trivial one: it consists of a file that must be read into Oracle.… Read More »

reading an HDFS file in Python

In this note, I show you how to get data from an HDFS platform into a Python programme. The idea is that we have data on HDFS and we would like to use these data in a Python programme. So, we must connect to HDFS from within a Python programme, read the data , transform… Read More »

Everything is SQL – the story of OBIEE

As one can imagine, SQL is the main engine to start loading a report in OBIEE. In principle, one has two kinds of queries. One query runs against the Oracle DBMS. This is the physical query that we know from any Oracle client. It can be found on the main main. Choose New > Analysis… Read More »

Using OBIEE spatial reporting

Using spatial reporting in OBIEE is not for the faint of heart. However it is also rewarding. The reports look great; it is new and henceforth exciting. It is challenging but the outcome stands out. However on the route to the reports, some obstacles must be overcome. Let me provide some thoughts on the obstacles… Read More »

Spatial Reporting in OBIEE

OBIEE allows you to create spatial reports. The idea is relatively simple. Instead of a tabular reports with rows and columns, we create a reports that are createad as a layer upon a map. So we have a map, with a layer of plotted values. When we have a report with a geographical component, such… Read More »

Latitudes and longitudes in the Netherlands

Getting geographical data on Holland is not a trivial matter. It took me a bit of tenacity to get the data. Hence I thought being a good idea to store my findings. I might need these data in the future. The first file that I found on the internet is a file with longitudes/ latitudes… Read More »

Oracle OBIEE – My First Report

Recently, I created my first OBIEE report. To be honest, my biggest problem was to identify which tools to use. I might overlook the clues, but it took me quite some time before I could identify the important tools that I had to use. Finally, I understood that two important tools must be used: [1]… Read More »