etc/postgresql/9.1/main/pg_hba.conf

   1 # CONNECTION  DATABASE  USER      AUTH      OPTIONS
   2 local         all       postgres  peer      map=admin
   3 local         all       backup    peer
   4 local         sameuser  all       peer      map=user
   5 local         samerole  all       peer      map=role
   6 hostssl       all       postgres  samehost  cert