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Essential PySpark for Scalable Data Analytics

You're reading from   Essential PySpark for Scalable Data Analytics A beginner's guide to harnessing the power and ease of PySpark 3

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Product type Paperback
Published in Oct 2021
Publisher Packt
ISBN-13 9781800568877
Length 322 pages
Edition 1st Edition
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Author (1):
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Sreeram Nudurupati Sreeram Nudurupati
Author Profile Icon Sreeram Nudurupati
Sreeram Nudurupati
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Table of Contents (19) Chapters Close

Preface 1. Section 1: Data Engineering
2. Chapter 1: Distributed Computing Primer FREE CHAPTER 3. Chapter 2: Data Ingestion 4. Chapter 3: Data Cleansing and Integration 5. Chapter 4: Real-Time Data Analytics 6. Section 2: Data Science
7. Chapter 5: Scalable Machine Learning with PySpark 8. Chapter 6: Feature Engineering – Extraction, Transformation, and Selection 9. Chapter 7: Supervised Machine Learning 10. Chapter 8: Unsupervised Machine Learning 11. Chapter 9: Machine Learning Life Cycle Management 12. Chapter 10: Scaling Out Single-Node Machine Learning Using PySpark 13. Section 3: Data Analysis
14. Chapter 11: Data Visualization with PySpark 15. Chapter 12: Spark SQL Primer 16. Chapter 13: Integrating External Tools with Spark SQL 17. Chapter 14: The Data Lakehouse 18. Other Books You May Enjoy

Introduction to SQL

SQL is a declarative language for storing, manipulating, and querying data stored in relational databases, also called relational database management systems (RDBMSes). A relational database contains data in tables, which in turn contain rows and columns. In the real world, entities have relationships among themselves, and a relational database tries to mimic these real-world relationships as relationships between tables. Thus, in relational databases, individual tables contain data related to individual entities, and these tables might be related.

SQL is a declarative programming language that helps you specify which rows and columns you want to retrieve from a given table and specify constraints to filter out any data. An RDBMS contains a query optimizer that turns a SQL declaration into a query plan and executes it on the database engine. The query plan is finally translated into an execution plan for the database engine to read table rows and columns into...

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