Step-by-Step Guide to Reset PostgreSQL User Password for Specific Version

To reset the password for a PostgreSQL user for a specific version of PostgreSQL on your Ubuntu system, you'll need to follow these steps. The process involves connecting to the correct instance of PostgreSQL and utilizing the psql command-line interface.

1) Identify the Correct PostgreSQL Version and Port:
$ pg_lsclusters

2) Connect to the Correct Version:
$ sudo -u postgres psql -p PORT

3) Change the User Password:
Once connected to the PostgreSQL prompt, you can reset the password of a specific PostgreSQL user by executing the following SQL command:
$ ALTER USER your_username WITH PASSWORD 'new_password';

4) Exit the PostgreSQL Shell:
After you successfully change the password, you can exit the psql prompt by typing:
$ \q

Notes:

Make sure that the user you are trying to modify exists in that specific PostgreSQL instance. You can check existing users by running\duin the PostgreSQL prompt.

If you encounter permission issues while connecting, ensure that you’re using the correct PostgreSQL superuser (usually postgres) to execute the ALTER USERcommand.

If PostgreSQL is configured to use the peer authentication method, you may have to change the authentication method in the pg_hba.conf file for the postgres user to md5in order to use password authentication.

Summary

By connecting to the specific PostgreSQL version and using the appropriate SQL command, you can easily reset any user's password on your Ubuntu system. Always make sure to use a secure password, especially in production environments.