Installing PostgreSQL 12 on Ubuntu
PostgreSQL is a powerful, open-source relational database management system (RDBMS) that is widely used for managing and storing data. In this article, we will walk you through the steps to install PostgreSQL 12 on Ubuntu.
Prerequisites
Before we start the installation process, ensure that the following prerequisites are met:
- A running Ubuntu system.
- A non-root user with sudo privileges.
- The apt package manager should be updated.
To update apt, run the following command:
sudo apt-get update
Install PostgreSQL 12 on Ubuntu
To install PostgreSQL 12 on Ubuntu, we will use the apt package manager. The first step is to add the PostgreSQL repository to our system. This repository contains the PostgreSQL packages that are required for the installation.
To add the repository, run the following command:
sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
Next, we will import the repository’s signing key to prevent package tampering. Run the following command to import the key:
wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
With the repository added and the signing key imported, we can now install PostgreSQL 12 by running the following command:
sudo apt-get update
sudo apt-get install postgresql-12
The installation process will take a few minutes to complete. Once the installation is finished, we can verify the installation by connecting to the PostgreSQL shell:
sudo -u postgres psql
This will open the PostgreSQL shell, where you can run SQL commands and interact with the database. To exit the shell, run the following command:
\q
Create a new PostgreSQL user
By default, PostgreSQL is installed with a default user named ‘postgres’. To create a new user, we can use the following command:
sudo -u postgres createuser --interactive
This will prompt you to enter the name of the new user, and you can set the appropriate privileges.
Create a new PostgreSQL database
To create a new database, we can use the following command:
sudo -u postgres createdb [database_name]
Replace [database_name] with the desired name for your new database.
Conclusion
In this article, we have covered how to install PostgreSQL 12 on Ubuntu and how to create a new user and database. PostgreSQL is a powerful relational database management system, and by following these steps, you can get it up and running on your Ubuntu system.
Accessing PostgreSQL from the command line
PostgreSQL provides a command-line client, psql, that allows you to connect to a database and run SQL commands. To connect to a database, you can use the following command:
psql -U [user_name] -d [database_name]
Replace [user_name] with the name of the user you want to connect as and [database_name] with the name of the database you want to connect to.
Configuring PostgreSQL
PostgreSQL is configured through a configuration file named postgresql.conf, which is located in the data directory of the PostgreSQL installation. The file contains a list of configuration parameters that you can use to customize your PostgreSQL installation.
For example, you can set the maximum number of connections, the memory size, and the authentication method used by PostgreSQL. It is important to carefully review the configuration file and make any necessary changes to ensure that your PostgreSQL installation is optimized for your specific needs.
Backup and Restore
It is important to regularly back up your PostgreSQL databases to protect against data loss. There are several methods for backing up PostgreSQL databases, including using pg_dump and pg_dumpall utilities.
pg_dump allows you to back up a single database, while pg_dumpall allows you to back up all databases. To backup a database using pg_dump, you can use the following command:
pg_dump -U [user_name] [database_name] > [backup_file].sql
Replace [user_name] with the name of the user you want to connect as, [database_name] with the name of the database you want to back up, and [backup_file] with the desired name for the backup file.
To restore a database backup, you can use the following command:
psql -U [user_name] [database_name] < [backup_file].sql
Replace [user_name] with the name of the user you want to connect as, [database_name] with the name of the database you want to restore, and [backup_file] with the name of the backup file.
PostgreSQL Monitoring
It is important to monitor the performance of your PostgreSQL installation to ensure that it is running optimally. There are several tools available for monitoring PostgreSQL, including the pg_stat_activity view, which provides information about the current activity on the database, and the pg_stat_database view, which provides information about database-wide statistics.
In addition, you can use the pg_top utility to monitor the performance of your PostgreSQL installation in real-time, just like the top utility for Unix-like systems. The utility provides information about active queries, database connections, and other performance-related statistics.
In conclusion, PostgreSQL is a powerful relational database management system, and by properly configuring, monitoring, and backing up your installation, you can ensure that your data is protected and your database is running optimally.
Popular questions
- How do I install PostgreSQL 12 on Ubuntu?
To install PostgreSQL 12 on Ubuntu, you need to first add the PostgreSQL repository to your system using the following command:
sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
Next, you need to import the repository signing key using the following command:
wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
Finally, you can install PostgreSQL 12 using the following command:
sudo apt update
sudo apt install postgresql-12
- How do I create a new database in PostgreSQL 12?
To create a new database in PostgreSQL 12, you can use the following command:
createdb -U [user_name] [database_name]
Replace [user_name] with the name of the user you want to connect as and [database_name] with the name of the database you want to create.
- How do I access a database in PostgreSQL 12?
To access a database in PostgreSQL 12, you can use the psql command-line client. To connect to a database, you can use the following command:
psql -U [user_name] -d [database_name]
Replace [user_name] with the name of the user you want to connect as and [database_name] with the name of the database you want to connect to.
- How do I backup a database in PostgreSQL 12?
To backup a database in PostgreSQL 12, you can use the pg_dump utility. To back up a database, you can use the following command:
pg_dump -U [user_name] [database_name] > [backup_file].sql
Replace [user_name] with the name of the user you want to connect as, [database_name] with the name of the database you want to back up, and [backup_file] with the desired name for the backup file.
- How do I restore a database backup in PostgreSQL 12?
To restore a database backup in PostgreSQL 12, you can use the psql command-line client. To restore a database backup, you can use the following command:
psql -U [user_name] [database_name] < [backup_file].sql
Replace [user_name] with the name of the user you want to connect as, [database_name] with the name of the database you want to restore, and [backup_file] with the name of the backup file.
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PostgreSQL
