Re: Cleaning up the INET/CIDR mess

On 2006-01-25, Greg Stark <gsstark@MIT.EDU> wrote:
> I have a question in a different direction. What is the meaning of the
> network mask in the inet data type anyways? Hosts don't have network masks,
> only networks.

As far as I can tell, the "inet" semantics are supposed to represent a
network interface, rather than just an address. So it designates a network
and a host within that network. This is a significant semantic overload,
which is not relevent to many applications and may be counterproductive
(for example, if you had a database of hosts and networks, the network info
would more correctly be accessed via a reference to a separate table than
embedded in the host address).

> If we could store inet in four bytes it would be vastly more efficient both
> in disk space usage and in cpu at runtime.

That's not reasonable for inet/cidr due to the need to support ipv6.

If you want that for ip4-only apps, that's why pgfoundry.org/projects/ip4r
exists. It is possible that ip4r will be extended to ipv6 addresses, but
most unlikely that it will ever implement the overloaded "inet" semantics.

-- 
Andrew, Supernews
http://www.supernews.com - individual and corporate NNTP services