How to Recover from a Lost PostgreSQL Password

Here's a general explanation of how to reset a PostgreSQL password:

1. Access the server: You'll need to log in to the server where PostgreSQL is installed. This could be a physical server you manage, or a virtual server you access remotely.

2. Edit the configuration file: Locate the pg_hba.conf file. This file determines how users can connect to the PostgreSQL server. You'll need to edit this file with administrative privileges.

3. Modify connection method: There are various ways to connect to PostgreSQL depending on your setup. In the pg_hba.conf file, look for the line referencing the "local" or "host" connection methods (depending on your setup). You'll want to temporarily change the authentication method to "trust" or "ident" (which don't require a password).

4. Restart the server: Once you've saved the changes to pg_hba.conf, restart the PostgreSQL service for the new configuration to take effect.

5. Connect and reset password: Now that password authentication is disabled, you should be able to connect to the PostgreSQL server. Once connected, you can use the ALTER USER command to set a new password for the desired user.

6. Secure the server: After setting the new password, don't forget to edit pg_hba.conf again to revert the authentication method back to a more secure option (like password authentication). Then restart the PostgreSQL service once more.

Important notes:

• Be cautious when modifying the pg_hba.conf file, as weakening authentication methods can expose your database to security risks.

Original configuration (example):

# Allow local connections without requiring a password
local   all             postgres                         trust

In this example, the local connection method allows any user (all) to connect to the database named postgres without a password (because trust is the authentication method).

Temporary modification (for password reset):

# Allow local connections without requiring a password (for reset)
local   all             postgres                         trust

Here, you'd keep the same line, as it allows connection for password reset.

Important: Remember, this configuration weakens security. Don't forget to revert it after resetting the password.

Securing the server after reset (example):

# Allow local connections requiring password authentication
local   all             postgres                         password

This line enforces password authentication for local connections to the postgres database.

Again, refer to the PostgreSQL documentation for your specific version for the most accurate instructions: https://stackoverflow.com/questions/61040249/how-to-reset-postgresql-password

Using a Superuser Account (if available):

• This method assumes you have access to a superuser account other than the one you forgot the password for. This could be another PostgreSQL user with administrative privileges.
• If such a user exists, you can log in to psql using that account and directly reset the password for the forgotten user with the ALTER USER command.

Recovery Mode (for advanced users):

• This method involves starting the PostgreSQL server in single-user mode. This mode allows only one user connection and bypasses some security measures.
• Warning: Be very cautious with this approach as it can be risky if not done properly. It's recommended for advanced users who understand the potential security implications.
• In recovery mode, you can potentially modify the password for the desired user directly within the database.

Here are some resources that explain these methods in more detail, but proceed with caution especially for recovery mode: