https://wiki.postgresql.org/wiki/Index-only_scans
This page is seriously out of date. It suggests they are not yet
implemented, but only being talked about.
Would someone who knows a lot about the subject (which is why I'm
sending this hackers, not web) like to take a whack at updating this?
Otherwise, I'd like to just replace the whole page with a discussion
of the limitations and trade-offs involved in using them as they
currently exist
Thanks,
Jeff