Installing PostgreSQL

Before you can work with PostgreSQL you need to install the server and the client tools on your machine. This lesson walks through installation on macOS, Linux (Ubuntu/Debian), and Windows, then verifies the installation.

Installing on macOS

The easiest method on macOS is Homebrew. If you do not have Homebrew, install it first from brew.sh.

# Install PostgreSQL (latest stable)
brew install postgresql@16

# Add the bin directory to your PATH (add this line to ~/.zshrc or ~/.bashrc)
export PATH="/opt/homebrew/opt/postgresql@16/bin:$PATH"

# Start the service
brew services start postgresql@16

Alternatively, download the graphical installer from the official PostgreSQL website (postgresql.org/download/macosx).

Installing on Ubuntu / Debian

# Update the package list
sudo apt update

# Install the server and client packages
sudo apt install -y postgresql postgresql-contrib

# The service starts automatically; verify it
sudo systemctl status postgresql

# Enable it to start on boot
sudo systemctl enable postgresql

Installing on Windows

Download the interactive installer from postgresql.org/download/windows. The installer includes:

• The PostgreSQL server
• pgAdmin 4 (a graphical administration tool)
• The Stack Builder utility for adding extensions

Run the installer, choose an installation directory, set a password for the postgres superuser, and accept the default port 5432.

Verifying the Installation

After installation, confirm the server is running and the client tools are available:

# Check the PostgreSQL version
psql --version

# Connect as the default superuser
# On macOS/Linux:
psql -U postgres

# On Linux if you get a peer authentication error, switch to the postgres OS user first:
sudo -u postgres psql

If you see the psql prompt (postgres=#) the installation succeeded.

The Default postgres User

PostgreSQL creates an OS user and a database superuser both named postgres during installation. This superuser can create databases, roles, and other superusers. You should create a dedicated role for your application rather than connecting as postgres in production.

Checking the Port

By default PostgreSQL listens on port 5432. You can verify this with:

# On Linux
sudo ss -tlnp | grep 5432

# On macOS
lsof -i :5432

With the server running and psql accessible, you are ready to start managing databases in the next lesson.