GRASS: 6.4.0: where is the postgresql (pg) driver?

[O. Hartmann]

Hello.
I desperately try to connect to a PostgreSQL DB server using GRASS 
(6.4.0 as from the recent ports). The documentation of GRASS, even the 
most recent one, reports using the 'driver=pg' option. Having already 
set up a database in PostgreSQL (server 9.0.4), the admin user properly 
specified is capable to connect from console (terminal) or pgadmin3 
client. But using GRASS, only 'dbf', 'sqlite' and 'ogr' as drivers are 
offered. I tried to figure out whether 'ogr' could cover postgresql 
connects, but there isn't any information about that, not even in GRASS' 
documentation (I haven't found any yet).
I suspect the 'pg'-driver isn't correctly included in GRASS so I'd like 
to ask someone already has used PostgreSQL as the DB backend for GRASS GIS.

Thanks in advance.

Oliver