Book Image

Pentaho Data Integration Beginner's Guide - Second Edition - Second Edition

By : María Carina Roldán
Book Image

Pentaho Data Integration Beginner's Guide - Second Edition - Second Edition

By: María Carina Roldán

Overview of this book

Capturing, manipulating, cleansing, transferring, and loading data effectively are the prime requirements in every IT organization. Achieving these tasks require people devoted to developing extensive software programs, or investing in ETL or data integration tools that can simplify this work. Pentaho Data Integration is a full-featured open source ETL solution that allows you to meet these requirements. Pentaho Data Integration has an intuitive, graphical, drag-and-drop design environment and its ETL capabilities are powerful. However, getting started with Pentaho Data Integration can be difficult or confusing. "Pentaho Data Integration Beginner's Guide - Second Edition" provides the guidance needed to overcome that difficulty, covering all the possible key features of Pentaho Data Integration. "Pentaho Data Integration Beginner's Guide - Second Edition" starts with the installation of Pentaho Data Integration software and then moves on to cover all the key Pentaho Data Integration concepts. Each chapter introduces new features, allowing you to gradually get involved with the tool. First, you will learn to do all kinds of data manipulation and work with plain files. Then, the book gives you a primer on databases and teaches you how to work with databases inside Pentaho Data Integration. Moreover, you will be introduced to data warehouse concepts and you will learn how to load data in a data warehouse. After that, you will learn to implement simple and complex processes. Finally, you will have the opportunity of applying and reinforcing all the learned concepts through the implementation of a simple datamart. With "Pentaho Data Integration Beginner's Guide - Second Edition", you will learn everything you need to know in order to meet your data manipulation requirements.
Table of Contents (26 chapters)
Pentaho Data Integration Beginner's Guide
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Best Practices
Index

Time for action – generating top average scores by copying and getting rows


In this section, we will split our work into two different transformations:

  • The first for reading the examination data and preparing it for further processing

  • The second for picking that prepared data and do some work with it

As said, you will need the same input files you've been working with. Once you have the files, you are ready for work:

  1. Open Spoon and create a new transformation.

  2. Just as you did in the previous section, define a named parameter with the name of the file to read, and read the examination file with a Text file input step.

    Note

    It's not mandatory to use the named parameter, but we do it for two reasons: first, for getting the habit of creating reusable transformations and second, because we will use that parameter in the last sections of this chapter.

  3. Use a Java Filter step to filter the students with low scores. As a filter enter the following:

    (english<75)&&(mathematics<75)&&(science...