Multiple auth types for a connection

Hi,

I am operating in an environment where we have regular users who will
authenticate via PAM and software users for automated processes that
would be more appropriate to authenticate via a password (encrypted or
not - irrelevant to this question). I have taken a look through the
documentation and google and done some trial and error, but I dont seem
to be able to get this working for a single client to be able to use
either method.

My 2 guesses involved changing the $PGDATA$/pg_hba.conf to try these
options:

1:
host all all 0.0.0.0/0 pam,password

(also tried space seperated as well as comma seperated)

2:
host all all 0.0.0.0/0 pam
host all all 0.0.0.0/0 password

In both cases (neither caused an error) the first type wins and the
other gives access denied.

Does anyone know if it is possible to overload auth types like this such
that if pam fails password would be tried?

Many thanks in advance,

Rob Cherry