This is a dummy root certificate file for PostgreSQL. To enable client side
authentication, add some certificates to it. Client certificates must be signed
with any certificate in this file to be accepted.

A reasonable choice is to just symlink this file to
/etc/ssl/certs/ssl-cert-snakeoil.pem; in this case, client certificates need to
be signed by the postgresql server certificate, which might be desirable in
many cases. See chapter "Server Setup and Operation" in the PostgreSQL
documentation for details (in package postgresql-doc-9.2).

  file:///usr/share/doc/postgresql-doc-9.2/html/ssl-tcp.html