ubuntu swap space

Hello Admin Group:
We are configuring Postgres on Ubuntu (LLynx) and trying to figure out what is the best way of dealing with swap since, Ubuntu does not automatically come with swap storage assigned.
Nothing but Postgres will be running on the machine.
I have read that we should assign twice the available RAM to swap, that seems like a lot.
Would Postgres ever use so much space? I understand if I were to load records that were gigs in size but that is very rare or at least I do not expect it in my case.

Any recommendations or best practices?
Thank you,
Sincerely,
Kasia