Book Image

Learn PostgreSQL - Second Edition

By : Luca Ferrari, Enrico Pirozzi
1 (2)
Book Image

Learn PostgreSQL - Second Edition

1 (2)
By: Luca Ferrari, Enrico Pirozzi

Overview of this book

The latest edition of this PostgreSQL book will help you to start using PostgreSQL from absolute scratch, helping you to quickly understand the internal workings of the database. With a structured approach and practical examples, go on a journey that covers the basics, from SQL statements and how to run server-side programs, to configuring, managing, securing, and optimizing database performance. This new edition will not only help you get to grips with all the recent changes within the PostgreSQL ecosystem but will also dig deeper into concepts like partitioning and replication with a fresh set of examples. The book is also equipped with Docker images for each chapter which makes the learning experience faster and easier. Starting with the absolute basics of databases, the book sails through to advanced concepts like window functions, logging, auditing, extending the database, configuration, partitioning, and replication. It will also help you seamlessly migrate your existing database system to PostgreSQL and contains a dedicated chapter on disaster recovery. Each chapter ends with practice questions to test your learning at regular intervals. By the end of this book, you will be able to install, configure, manage, and develop applications against a PostgreSQL database.
Table of Contents (22 chapters)
20
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21
Index

Basic concepts

First of all, let’s try to understand why we have to partition data. We should start by saying that a common constant of all databases is that their size always grows. It is, therefore, possible that a database, after a few months of growth, can reach a size of gigabytes, terabytes, or even petabytes.

Another thing we must always keep in mind is that not all tables grow at the same rate or to the same level; some tables are bigger than others and some indexes too are bigger than other indexes.

We also need to know that there is a part of our server’s RAM, shared among all the PostgreSQL processes, that is used to manage the data present in tables. This part of the server’s RAM is called shared_buffers.

The way PostgreSQL works is as follows:

  1. Data is taken from hard disks.
  2. Data is placed in shared buffers.
  3. Data is processed in shared buffers.
  4. Data is downloaded to disks.

Typically, in a dedicated...