Configure a repository

Install the required Gnu Privacy Guard dependency

$ sudo apt -y install gnupg2

Import the PGP signing key for the given repository

$ wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -

Add PostgreSQL apt repository

$ echo "deb http://apt.postgresql.org/pub/repos/apt/ `lsb_release -cs`-pgdg main" | sudo tee /etc/apt/sources.list.d/pgdg.list

Install PostgreSQL and PostGIS

In this step, you must first install PostgreSQL

$ sudo apt -y install postgresql-12 postgresql-client-12

Then install PostGIS

$ sudo apt install postgis postgresql-12-postgis-3

After that, install all the necessary control packages

$ sudo apt-get install postgresql-12-postgis-3-scripts

Log into PostgreSQL and enable PostGIS

First, log in as superuser

$ sudo su - postgres

Next, create a new PostgreSQL user

$ createuser exampleuser

After that, set a password for the new user

$ psql -c "alter user exampleuser with password 'yourPassword'"

Create a new database

$ createdb my_db -O exampleuser

Connect to database

$ psql -d my_db

Enable PostGIS Database Extension

my_db=# CREATE EXTENSION postgis;

Test the PostGIS extension

my_db=# SELECT PostGIS_version();

The most important task of the administrator is regular backup, it is an integral part of working with databases. The first thing to start is updating all system packages

Updating System Packages

Before starting, update the packages on your server

sudo apt-get update -y
sudo apt-get upgrade -y

PostgreSQL installation

PostgreSQL is available in the Ubuntu 18.04 repository and can be installed very simply with the following command:

sudo apt-get install postgresql postgresql-contrib

Then you should start the postgresql service and enable it at boot time:

sudo systemctl start postgresql
sudo systemctl enable postgresql

Backup Instructions

PostgreSQL comes with the pg_dump utility for calling information from the database to a file. You can run this utility from the command line interface. For example, if you want to back up one database, run the following command:

sudo pg_dump -U user_name database_name > backup_file

IMPORTANT! The command must be run as root.

You can follow another way: backup the database by logging in as a postgres user:

sudo su - postgres
pg_dump postgres > postgres.bak

This command (which is indicated above, respectively) backs up the default database postgres.

Also, using the command below, it is possible to backup a remote database:

pg_dump -U user_name -h remote_ip_address -p remote_port database_name > backup_file

If you want to backup all the databases on your system, then pg_dumpall then you can use:

sudo pg_dumpall -U user_name > backup_file

Restore Instructions

Next, we will discuss how to restore the database created by the pg_dump command using the psql command, but first you need to create a empty base with name new_database

sudo -u postgres psql
createdb -T template0 new_database

Then you need to redirect the database dump caused by backup_files with the following command:

psql new_database < backup_file

It happens that errors are made during the backup process, and you urgently need to stop the recovery process when an error occurs, run the following command:

psql --set ON_ERROR_STOP=on new_database < backup_file

To restore the databases created by the pg_dumpall command, transfer the file to sql. You can use this command:

psql -U user_name -f backup_file   

We recommend that you regularly store and back up!