Book Image

Pentaho 3.2 Data Integration: Beginner's Guide

Book Image

Pentaho 3.2 Data Integration: Beginner's Guide

Overview of this book

Pentaho Data Integration (a.k.a. Kettle) is a full-featured open source ETL (Extract, Transform, and Load) solution. Although PDI is a feature-rich tool, effectively capturing, manipulating, cleansing, transferring, and loading data can get complicated.This book is full of practical examples that will help you to take advantage of Pentaho Data Integration's graphical, drag-and-drop design environment. You will quickly get started with Pentaho Data Integration by following the step-by-step guidance in this book. The useful tips in this book will encourage you to exploit powerful features of Pentaho Data Integration and perform ETL operations with ease.Starting with the installation of the PDI software, this book will teach you all the key PDI concepts. Each chapter introduces new features, allowing you to gradually get involved with the tool. First, you will learn to work with plain files, and to do all kinds of data manipulation. Then, the book gives you a primer on databases and teaches you how to work with databases inside PDI. Not only that, you'll be given an introduction to data warehouse concepts and you will learn to load data in a data warehouse. After that, you will learn to implement simple and complex processes.Once you've learned all the basics, you will build a simple datamart that will serve to reinforce all the concepts learned through the book.
Table of Contents (27 chapters)
Pentaho 3.2 Data Integration Beginner's Guide
Credits
Foreword
The Kettle Project
About the Author
About the Reviewers
Preface
Index

Time for action – reading all your files at a time using a single Text file input step and regular expressions


You could do the same thing you did above by using a different notation. Follow these instructions:

  1. Open the transformation and edit the configuration windows of the input step.

  2. Delete the lines with the names of the files.

  3. In the first row of the grid, type C:\pdi_files\input\ under the File/Directory column, and group[1-4]\.txt under the Wildcard (Reg.Exp.) column.

  4. Click the Show filename(s)... button. You'll see the list of files that match the expression.

  5. Close the tiny window and click Preview rows to confirm that the rows shown belong to the four files that match the expression you typed.

What just happened?

In this particular case, all filenames follow a pattern—group1.txt, group2.txt, and so on. In order to specify the names of the files, you used a regular expression. In the column File/Directory you put the static part of the names, while in the Wildcard (Reg.Exp.) column...