Book Image

Pentaho Data Integration Cookbook - Second Edition - Second Edition

Book Image

Pentaho Data Integration Cookbook - Second Edition - Second Edition

Overview of this book

Pentaho Data Integration is the premier open source ETL tool, providing easy, fast, and effective ways to move and transform data. While PDI is relatively easy to pick up, it can take time to learn the best practices so you can design your transformations to process data faster and more efficiently. If you are looking for clear and practical recipes that will advance your skills in Kettle, then this is the book for you. Pentaho Data Integration Cookbook Second Edition guides you through the features of explains the Kettle features in detail and provides easy to follow recipes on file management and databases that can throw a curve ball to even the most experienced developers. Pentaho Data Integration Cookbook Second Edition provides updates to the material covered in the first edition as well as new recipes that show you how to use some of the key features of PDI that have been released since the publication of the first edition. You will learn how to work with various data sources – from relational and NoSQL databases, flat files, XML files, and more. The book will also cover best practices that you can take advantage of immediately within your own solutions, like building reusable code, data quality, and plugins that can add even more functionality. Pentaho Data Integration Cookbook Second Edition will provide you with the recipes that cover the common pitfalls that even seasoned developers can find themselves facing. You will also learn how to use various data sources in Kettle as well as advanced features.
Table of Contents (21 chapters)
Pentaho Data Integration Cookbook Second Edition
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
References
Index

Executing part of a job several times until a condition is true


Suppose that you have a list of tasks that have to be repeated while or until a condition is true (or false). If you know about programming languages, think of this as an analogy of a while or repeat until loop. Kettle allows you to implement these kinds of iterations and this recipe explains how to do it.

For the recipe, you will use one of the transformations described in the introduction of this chapter—the transformation that generates random numbers and writes them to a file. You will execute the transformation repeatedly and keep track of the number of lines written to those files. You will continue executing the transformation as long as the total number of written lines is less than 25.

Getting ready

You will need the transformation that generates random numbers described in the introduction. If, instead of downloading the transformation you created it yourself, you will have to do a quick fix in order to make Kettle save...