Re: IPv6 link-local addresses and init data type

Markus Wanner <markus@bluegap.ch> writes:
> Considering that Postgres is not unlikely to write INET types to
> permanent storage, its values should better survive a reboot. And while
> I have some doubts about persistence of interface names, those clearly
> have a higher chance of surviving a reboot compared to interface
> indices. Therefore, I'd advocate resolving interface indices (if given)
> to interface names using if_indextoname(3) and let INET types store only
> names.

What will you do on machines without if_indextoname()?  More importantly,
on what basis do you conclude that the inet type will only be asked to
store link-local addresses that are currently valid on the local machine?
It is not very hard to think of applications where that wouldn't be the
case.

I think a better plan is just to store the zone string verbatim.  It is
not our job to check its validity or try to determine which spellings
are equivalent.
        regards, tom lane