Book Image

Learning Spark SQL

By : Aurobindo Sarkar
Book Image

Learning Spark SQL

By: Aurobindo Sarkar

Overview of this book

In the past year, Apache Spark has been increasingly adopted for the development of distributed applications. Spark SQL APIs provide an optimized interface that helps developers build such applications quickly and easily. However, designing web-scale production applications using Spark SQL APIs can be a complex task. Hence, understanding the design and implementation best practices before you start your project will help you avoid these problems. This book gives an insight into the engineering practices used to design and build real-world, Spark-based applications. The book's hands-on examples will give you the required confidence to work on any future projects you encounter in Spark SQL. It starts by familiarizing you with data exploration and data munging tasks using Spark SQL and Scala. Extensive code examples will help you understand the methods used to implement typical use-cases for various types of applications. You will get a walkthrough of the key concepts and terms that are common to streaming, machine learning, and graph applications. You will also learn key performance-tuning details including Cost Based Optimization (Spark 2.2) in Spark SQL applications. Finally, you will move on to learning how such systems are architected and deployed for a successful delivery of your project.
Table of Contents (19 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Introducing feature engineering


Feature engineering is the process of using domain knowledge of the data to create features that are key to applying machine learning algorithms. Any attribute can be a feature, and choosing a good set of features that helps solve the problem and produce acceptable results is to the whole process. This step is often the most challenging aspect of machine learning applications. Both the quality and quantity/number of features greatly influences the overall quality of the model.

Better features also means more flexibility because they can result in good results even when less than optimal models are used. Most ML models can pick up on the structure and patterns in the underlying data, reasonably well. The flexibility of good features allows us to use less complex models that are faster and easier to understand and maintain. Better features also typically result in simpler models. Such make it easier to select the right models and the most optimized parameters...