Change a Password for PostgreSQL on Linux via Command Line

PostgreSQL supports many client authentication methods, but in this case we’re only going to concern ourselves with two: password and md5.

Preflight Check

• These instructions are intended specifically for changing a password in PostgreSQL.
• I’ll be working from a Liquid Web Core Managed CentOS 7 server, and I’ll be logged in as root.
• PostgreSQL is installed per our tutorial on: How to Install and Connect to PostgreSQL on CentOS 7.

Step #1: Switch to the PostgreSQL User: postgres

If you’re working from a default PostgreSQL installation, then PostgreSQL will be configured with the user postgres.

Since we’re logged in as root, and we’re assuming that root doesn’t have a user for PostgreSQL, switch to the default PostgreSQL user: postgres:

su - postgres

… then attempt a connection to PostgreSQL:

psql

… enter your password at the prompt:

Password:

… the correct, valid response will be similar to:

psql (9.3.9)
Type "help" for help.

postgres=#

Step #2: Add/Change the Password for the PostgreSQL User: postgres

Use the following command to change the password for your current user, which is now postgres:

\password

Enter your new password, and then enter it again to confirm it:

Enter new password:
Enter it again:

Now quit the PostgreSQL interface:

\q

Bonus Information!

You can do all the step one in exactly one command:

su -c "psql" - postgres