Book Image

MySQL Admin Cookbook

By : Daniel Schneller, Udo Schwedt
Book Image

MySQL Admin Cookbook

By: Daniel Schneller, Udo Schwedt

Overview of this book

<p>MySQL is the most popular open-source database and is also known for its easy set up feature. However, proper configuration beyond the default settings still is a challenge, along with some other day-to-day maintenance tasks such as backing up and restoring, performance tuning, and server monitoring. These tasks have not been covered thoroughly in the default documentation.<br /><br />This book provides both step-by-step recipes and relevant background information on these topics and more. It covers everything from basic to advanced aspects of MySQL administration and configuration. One of the things you are really going to love about this book is that all recipes are based on real-world experience and were derived from proven solutions used in an enterprise environment.<br /><br />This book shows you everything you need to know about MySQL Administration. You will learn to set up MySQL replication to manage load balancing and deal with online backup and fail-over scenarios. As you consider the benefits of backing up, you might like to back up your database efficiently with advanced techniques covered in this book.<br /><br />The book demonstrates how to create, modify, and delete indexes. You will also learn to identify duplicate indexes, which hinder your MySQL server performance. This book focuses on administration tasks and will help you as an administrator to optimize the database for efficiency and reliability.<br /><br />You will learn to manage data efficiently by inserting data in existing database content and importing and exporting databases. The sooner you learn about taking advantage of metadata from this book, the sooner you can start using the space efficiently. Get to know about managing users and assigning privileges and regaining lost administrative user credentials. Finally, learn to manage the database schema by customizing it to automate database schema evolution in the context of application updates.</p>
Table of Contents (16 chapters)
MySQL Admin Cookbook
Credits
About the Authors
About the Reviewers
Preface
Index

Deleting all data from large tables


Almost everyone who works with databases experiences the constant growth of the data stored in their database and it is typically well beyond the initial estimates. Because of that you often end up with rather large data sets. Another common observation is that in most databases, there are some tables that have a special tendency to grow especially big.

If a table's size reaches a virtual threshold (which is hard to define, as it depends heavily on the access patterns and the data structures), it gets harder and harder to maintain and performance degradation might occur. From a certain point on, it is even difficult to get rid of data in the table again, as the sheer number of records makes deletion a pretty expensive task. This particularly holds true for storage engines with Multi-Version Concurrency Control (MVCC): if you order the database to delete data from the table, it must not be deleted right away because you might still roll back the deletion...