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

Executing jobs in an iterative way


For a long time, PDI developers used to ask, can I run a Job inside a transformation? The answer was definitely a no. In order to solve the requirement, the solution was to create jobs and transformations nested in complex ways. Now you can avoid all that unnecessary work by looping jobs in an easier way. There is a Job Executor step—analogous to the Transformation Executor that you know—that can easily be configured to loop over the rows in a dataset.

Using Job executors

The Job Executor is a PDI step that allows you to execute a Job several times simulating a loop. The executor receives a dataset, and then executes the Job once for each row or a set of rows of the incoming dataset.

To understand how this works, we will build a very simple example. The Job that we will execute will have two parameters: a folder and a file. It will create the folder, and then it will create an empty file inside the new folder. Both the name of the folder and the name of the...