tclodbc (http://sourceforge.net/projects/tclodbc) and libiodbc-2.50.3
(http://www.iodbc.org/dist/libiodbc-2.50.3.tar.gz).  I could not
get either to work... postgres would not find the global odbcinst.ini
file.  I traced this to src/interfaces/odbc/gpps.c -- here are the
many things I think are wrong:

Run tclodbc and do a ``database db <DSNname>'' where ``DSNname'' is
one of the DSN's in /usr/local/etc/odbcinst.ini (or wherever the
global ini file is installed.)  The result is always the error
message that ``one of server,port,database,etc. are missing''.

Run libiodbc-2.50.3/samples/odbctest <DSNname>.  The command fails
to connect to the database and just exits.

Dave Bodenstab