Preface

The first edition of this book was written in a one week break between jobs and improved during COVID lockdown in 2020. I honestly wasn’t sure how many people wanted to read a book about building a query engine from scratch. It turns out that there are quite a few.

This second edition is a significant revision with clearer explanations, better code organization, and expanded coverage of topics like joins, subqueries, and distributed query execution.

This book is not academic in nature. It aims to be a practical, straightforward guide. The feedback from readers has been encouraging, so thank you to everyone who provided suggestions and corrections. I hope this edition serves as an even better foundation for understanding query engines.

Feedback

I welcome feedback on this book. You can contact me on LinkedIn or through the Leanpub forum.

This book is also available for purchase in ePub, MOBI, and PDF format from https://leanpub.com/how-query-engines-work

Copyright © 2020-2025 Andy Grove. All rights reserved.