"Secure enough" depends a lot on your requirements.
I would say that that is good enough for normal purposes. An easy improvement would be to use scram-sha-256
instead of md5
(don't forget to change the password_encryption
parameter and set a new password).
If your database contains the secret algorithm that the NSA uses to break TLS encryption, you might want to use a different authentication method like Kerberos that uses central identity management rather than database passwords.