The following is in reference to the download found at :

http://rdbi.sourceforge.net/

Which untars into Rdbi.PGsql/

"configure" script is outdated. Delete it, and run "autoconf" followed by
./configure

read the warning:

if test $PG_INCLUDE_DIR_NOT_FOUND
then

        echo
        echo I could not find your PostgreSQL client headers\!
        echo Use --with-pgsql-includes=PATH\; if running R\'s INSTALL\,
        echo use --configure-args=\'--with-pgsql-includes=PATH\'\; or
        echo set PG_INCLUDE_DIR in your environment to the library path\,
        echo and rerun the configure/install\.
        echo
        exit 1;

fi

and instead of :

#!/bin/sh
./configure --with-pgsql-libraries=/usr/local/pgsqlcvs/lib --with-pgsql-includes=/usr/local/pgsqlcvs/lib

type instead

./configure --configure-args=\'with-pgsql-libraries=/usr/local/pgsqlcvs/lib --with-pgsql-includes=/usr/local/pgsqlcvs/lib\'
HOWEVER,that, too, "is a dead end". In fact, there is no makefile!