The title says it all. In Oracle, we can easily get the OS user using:
select sys_context( 'userenv', 'os_user' ) from dual;
I usually use that for logging purposes (know who inserted/updated what and when). I searched for something similar for Postgres (I am new to it) but I could not find. Isn't that possible?
In general, if Postgres does not allow me to get the OS user, does it allow retreiving any kind of information outside the DB itself (e.g.: IP of host, .. etc.)?