Book Image

MySQL 8 Cookbook

By : Karthik Appigatla
Book Image

MySQL 8 Cookbook

By: Karthik Appigatla

Overview of this book

MySQL is one of the most popular and widely used relational databases in the World today. The recently released MySQL 8 version promises to be better and more efficient than ever before. This book contains everything you need to know to be the go-to person in your organization when it comes to MySQL. Starting with a quick installation and configuration of your MySQL instance, the book quickly jumps into the querying aspects of MySQL. It shows you the newest improvements in MySQL 8 and gives you hands-on experience in managing high-transaction and real-time datasets. If you've already worked with MySQL before and are looking to migrate your application to MySQL 8, this book will also show you how to do that. The book also contains recipes on efficient MySQL administration, with tips on effective user management, data recovery, security, database monitoring, performance tuning, troubleshooting, and more. With quick solutions to common and not-so-common problems you might encounter while working with MySQL 8, the book contains practical tips and tricks to give you the edge over others in designing, developing, and administering your database effectively.
Table of Contents (20 chapters)
Title Page
Dedication
Packt Upsell
Contributors
Preface
Index

Adding indexes


Without an index, MySQL must scan the entire table row by row to find the relevant rows. If the table has an index on the columns that you are filtering for, MySQL can quickly find the rows in the big data file without scanning the whole file.

MySQL can use an index for filtering of rows in WHERE, ORDER BY, and GROUP BY clauses, and also for joining tables. If there are multiple indexes on a column, MySQL chooses the index that gives maximum filtering of rows.

You can execute the ALTER TABLE command to add or drop the index. Both index addition and dropping are online operations and do not hinder the DMLs on the table, but they take lot of time on larger tables.

Primary key (clustered index) and secondary indexes

Before you proceed further, it is important to understand what a primary key (or clustered index) is, and what a secondary index is.

InnoDB stores rows in a primary key in order to speed up queries and sorts involving the primary key columns. This is also called an index...