Book Image

Learning Pentaho Data Integration 8 CE - Third Edition

Book Image

Learning Pentaho Data Integration 8 CE - Third Edition

Overview of this book

Pentaho Data Integration(PDI) is an intuitive and graphical environment packed with drag-and-drop design and powerful Extract-Tranform-Load (ETL) capabilities. This book shows and explains the new interactive features of Spoon, the revamped look and feel, and the newest features of the tool including transformations and jobs Executors and the invaluable Metadata Injection capability. We begin with the installation of PDI software and then move on to cover all the key PDI concepts. Each of the chapter introduces new features, enabling you to gradually get practicing with the tool. First, you will learn to do all kind of data manipulation and work with simple plain files. Then, the book teaches you how you can work with relational databases inside PDI. Moreover, you will be given a primer on data warehouse concepts and you will learn how to load data in a data warehouse. During the course of this book, you will be familiarized with its intuitive, graphical and drag-and-drop design environment. By the end of this book, you will learn everything you need to know in order to meet your data manipulation requirements. Besides, your will be given best practices and advises for designing and deploying your projects.
Table of Contents (23 chapters)
Title Page
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface

Defining and using Kettle variables


In Chapter 3, Creating Basic Task Flows, you were introduced to Kettle variables. This section resumes the subject by explaining to you all the kinds of Kettle variables, how to define them, and all the ways to use them.

Introducing all kinds of Kettle variables

Kettle variables can be defined in several ways, and with the different scope. You already know about predefined variables and variables defined in the kettle.properties file, but there are more options. The following subsections summarize them all.

Explaining predefined variables

Predefined variables are Kettle variables mainly related to the environment in which PDI is running. These variables are ready to be used both in Jobs and Transformations and their scope is the Java Virtual Machine (JVM).

The following table lists some of the most used predefined variables:

Subject

Predefined variables

Operating system

${os.name}${os.version}

Current user

${user.home}${user.name}${user.timezone}${user.language...