auth sufficient pam_postgresok.so
pam_postgresok.so is designed to check that the real UID of the calling process belongs to the "postgres" user and equal to 26 (the value assigned to that user on Red Hat Linux systems).
Enable module debugging. The module will log its progress to syslog.
Let's hope not, but if you find any, please report them via the "Bug Track" link at http://bugzilla.redhat.com/bugzilla/
Fernando Nasser <email@example.com>