Re: exclusion constraint for ranges of IP

In article <CAF36091-203E-4C10-AA53-7D9087114D35(at)unicell(dot)co(dot)il>,
Herouth Maoz <herouth(at)unicell(dot)co(dot)il> writes:

> Hi,
> I'm designing a new database. One of the table contains allowed IP ranges for a customer (Fields: customer_id, from_ip, to_ip) which is intended to check - if an incoming connection's originating IP number falls within the range, it is identified as a particular customer.

> Naturally, I'd like to have constraints on the table that prevent entering of ip ranges that overlap. Is there a way to do that with exclusion constraints? Or do I have to define a new type for this?

This "new type" already exists: ip4r, which can be found in pgfoundry.
With it you can do

CREATE TABLE mytbl (
iprange ip4r NOT NULL,
...,
CONSTRAINT range_check CHECK ((NOT overlap(iprange)))
);