ident authentication

Hi,

I am trying to test different kinds of authentication in postgres.

I'm to find a efficient way to link the OS user with the postgres user.
This is to help for auditing purpose. This is similar to the query
raised by another postgres user.

As suggested by Tom to use ident, i tried setting up ident but it isn't
working.

In the hba.conf file, i add the below entry

local all all ident sameuser

The user logged in at OS level is "abc". I created a user "abc" in
postgres but when i do "psql -U abc -d dbname", i get the below error:

FATAL: Ident authentication failed for user "abc"

Should i put an entry in pg_ident.conf file?

Is using ident still the right way to go? Is LDAP a better option
because when we login to the server, we login with our LDAP username and
password.

Thanks and Regards,
Shilpa