DSN settings

Hi -

I'm looking for a good source of documentation for the DSN settings
available to the postgres drivers. I have found several sites with
sample odbc.ini entries but nothing that has a comprehensive list.

The reason I'm looking for this is that the following setting:

ConnSettings        = set extra_float_digits to 0

doesn't cause any complaints, but also doesn't seem to have any effect.
The only reference in the debug log for that DSN connection to the float
digits is:

Exec_with_parameters_resolved: copying statement params: trans_status=1,
len=27, stmt='set extra_float_digits to 2'

We tried this with several versions of postgres drivers, including the
latest release of 8.02.0500.

Any help with location of documentation and/or problems with the
ConnSettings greatly appreciated!

Mija