Book Image

PostgreSQL 11 Administration Cookbook

By : Simon Riggs, Gianni Ciolli, Sudheer Kumar Meesala
Book Image

PostgreSQL 11 Administration Cookbook

By: Simon Riggs, Gianni Ciolli, Sudheer Kumar Meesala

Overview of this book

PostgreSQL is a powerful, open source database management system with an enviable reputation for high performance and stability. With many new features in its arsenal, PostgreSQL 11 allows you to scale up your PostgreSQL infrastructure. This book takes a step-by-step, recipe-based approach to effective PostgreSQL administration. The book will introduce you to new features such as logical replication, native table partitioning, additional query parallelism, and much more to help you to understand and control, crash recovery and plan backups. You will learn how to tackle a variety of problems and pain points for any database administrator such as creating tables, managing views, improving performance, and securing your database. As you make steady progress, the book will draw attention to important topics such as monitoring roles, backup, and recovery of your PostgreSQL 11 database to help you understand roles and produce a summary of log files, ensuring high availability, concurrency, and replication. By the end of this book, you will have the necessary knowledge to manage your PostgreSQL 11 database efficiently.
Table of Contents (19 chapters)
Title Page
Copyright and Credits
About Packt
Contributors
Preface
Index

Usage of disk space by temporary data


In addition to ordinary persistent tables, you can also create temporary tables.

PostgreSQL may use temporary files for query processing if it can't fit all the necessary data into memory.

So, how do you find out how much data is being used by temporary tables and files? You can do this by using any untrusted embedded language, or directly on the database host.

Getting ready

You have to use an untrusted language, because trusted languages run in a sandbox, which prohibits them from directly accessing the host filesystem.

How to do it…

Perform the following steps:

  1. First, check whether your database defines special tablespaces for temporary files, as follows:
SELECT current_setting('temp_tablespaces');
  1. As explained later on in this recipe, if the setting is empty, it means that PostgreSQL is not using temporary tablespaces, and temporary objects will be located in the default tablespace for each database.
  2. On the other hand, if temp_tablespaces has one or more tablespaces...