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 – counting frequent words by coding in JavaScript


In Chapter 4, Filtering, Searching, and Performing Other Useful Operations with Data, you created a transformation that read a file and counted frequent words. In this section, you will create a variant of that transformation by replacing some of the steps with a piece of JavaScript code.

  1. Open the transformation from the section named Counting frequent words by filtering from Chapter 4, Filtering, Searching, and Performing Other Useful Operations with Data. Select the first two steps—the Text file input and the Split field to rows steps—and copy them to a new transformation.

  2. From the Scripting category of steps, select and drag a Modified Java Script Value step to the work area. Create a hop from the Split field to rows step toward this. You will have the following:

  3. Double-click on the Modified Java Script Value step—MJSV from now on—and under the text //Script here, type the following:

    var len_word = word.length;
    var u_word ...