Book Image

Learn PostgreSQL

By : Luca Ferrari, Enrico Pirozzi
Book Image

Learn PostgreSQL

By: Luca Ferrari, Enrico Pirozzi

Overview of this book

PostgreSQL is one of the fastest-growing open source object-relational database management systems (DBMS) in the world. As well as being easy to use, it’s scalable and highly efficient. In this book, you’ll explore PostgreSQL 12 and 13 and learn how to build database solutions using it. Complete with hands-on tutorials, this guide will teach you how to achieve the right database design required for a reliable environment. You'll learn how to install and configure a PostgreSQL server and even manage users and connections. The book then progresses to key concepts of relational databases, before taking you through the Data Definition Language (DDL) and commonly used DDL commands. To build on your skills, you’ll understand how to interact with the live cluster, create database objects, and use tools to connect to the live cluster. You’ll then get to grips with creating tables, building indexes, and designing your database schema. Later, you'll explore the Data Manipulation Language (DML) and server-side programming capabilities of PostgreSQL using PL/pgSQL, before learning how to monitor, test, and troubleshoot your database application to ensure high-performance and reliability. By the end of this book, you'll be well-versed with the Postgres database and be able to set up your own PostgreSQL instance and use it to build robust solutions.
Table of Contents (27 chapters)
Section 1: Getting Started
Section 2: Interacting with the Database
Section 3: Administering the Cluster
Section 4: Replication
Section 5: The PostegreSQL Ecosystem

Exploring configuration files and parameters

The main configuration file for PostgreSQL is postgresql.conf, a text-based file that drives the cluster when it starts.
Usually, when changing the configuration of the cluster, you have to edit the postgresql.conf file to write the new settings and, depending on the context of the settings you have edited, to issue a cluster SIGHUP signal (that is, reload the configuration) or restart it.

Every configuration parameter is associated with a context, and depending on the context, you can apply changes with or without a cluster restart. In particular, available contexts are the following:

  • internal: A group of parameters that are set at compile-time and therefore cannot be changed at runtime.
  • postmaster: All the parameters that require the cluster to be restarted (that is, to kill the postmaster process and start it again) to activate them.
  • sighup: All the configuration parameters that can be applied with a SIGHUP signal sent to the postmaster...