Category: nice to know

As a first example on how to read an XML file, I show how an XML file can be read with a PLSQL programme. The logic is quite simple. We know that XML can be declared as an XMLtype. Once that is known, we declare the full XML file as an object that is read…

This programme creates an Oracle procedure. This Oracle programme has a loop. Within that loop, one record is read from a table. The content of that record is used within the loop. I want to retain this programme for future usage. I tend to forget how such a table is created within a cursor and…

I now work in an organisation where they often use SAS as a means to maintain Oracle tables. For some reason, people approach me to create such connection. Dunno why but they seem to think that I can do this. I developped a method how to set this up. Generally speaking, SAS offers three ways…

I regularly happens to me that I want to generate a random set of records in an Oracle table. That could happen if we want to assess performance of a certain procedure. Or (other example) if we want to estimate the size of a table. A great thing of Oracle is the random function where…

It is possible to use Sqoop to directly load from a RDBMS into Hive. This opens interesting possibilities. Data that are stored in a RDBMS and that need to be analysed on a cheaper platform, can be migrated via Sqoop to a Hadoop platform. Sqoop is generaly seen as a reliable medium to undertake such…

It is good to realise that Hive is built upon a mapreduce framework. The idea is that Hive is developed by facebook to facilitate analysis on Hadoop files. It is possible to use some kind of a SQL dialect in stead of a Python or a java programme to do your analysis. When a Hive…

In this blog, I will discuss the word count problem as done with Python. It is often used to show how map reduce works. In most examples, it is developed within the context of a Java programme. The idea is that the programme is split into two stages. In one stage, calculations are made on…

  In my view, the new development that we see now is building links to a Hadoop platform. One such development is building ODBC drivers that allow windows tools to access a Hadoop platform. An an example, one may think of Excel accessing tables on Hive. Think for a second on the possibilities: one may…

Recently, I revisited Pig. Pig is a language that allows you to analyse data sets in a Hadoop environment. It is created at Yahoo to circumvent the technicalities of creating a MapReduce Java job. Yahoo claims that most of her queries on a Hadoop platform can be replaced by a Pig script. As Pig is…

A few days ago, I was asked to load some tables in Oracle. A rather trivial question but I wasn’t sure if enough tablespace was left. From the table definition, I came to know what tablespace was used. After that I ran below query to see how much tablespace was actually left. I want to…