Qualified Names

I have the following SQL statement

SELECT * FROM system_user

JOIN

other_user

ON

System_user.userid = other_user.userid

I get back cols along with both the "userid" cols in both the tables. These
cols are however not fully qualified.

Is there anywhere to configure postgres to always return a col in the format
"tablename.columnname"? I would like to have this for ALL columns even if
they are not duplicates. This should be done when the SELECT is done with a
"*" and not a explicit select list that I have to build on my own.

Thanks,

Girish