Re: cidr & inet types

At 08:25 PM 7/15/2003 -0400, Tim Conrad wrote:

>And, the values are actually all there:
>nettest=> select * from cidr;
> net
>-------------
> 10.1.0.0/22
> 10.1.4.0/22
> 10.1.0.0/20
>(3 rows)
>
>While it seems intelligent enough to know that 10.1.1.0/22 would overlap, it
>doesn't know that 10.1.0.0/20 would envelop other networks that already exist
>in it's dataset. Am I doing something incorrectly here?

And what if 10.1.0.0/20 covers the range of other networks? Even if Big Org
network totally covers the Dept A and Dept B networks, why shouldn't you be
able to insert all 3? The Unique constraint should prevent people from
successfully inserting Big Org Network more than once, but that's about it.

You're assuming a much narrower range of usage/application for cidr stuff.

>While it's possible it's just my viewpoint, it seems that this is kind of
>weird
>behavior. If the datatype has any notion of networks and that data being
>'unique' shouldn't it also know about netmasks? I guess it's a different kind
>of unique than people are used to seeing. But, you can't have two networks,
>one 10.1.0.0/22 and 10.1.0.0/20 on the same wire, or connected to a
>router, or whatever.

You can have two networks 10.1.0.0/22 and 10.1.0.0/20 on the same router
and on the same wire too.

A router could have two different routes: packets to 10.1.0.0/22 will be
sent via 10.1.1.1 and the rest matching 10.1.0.0/20 via 10.1.1.2.

The more specific route takes precedence. But that does not exclude the
existence of a more general network.

You might be able to create a functional index that does what you want. I
don't know how but I think it could be possible.

Regards,
Link.