Re: Best way to index IP data? - Mailing list pgsql-performance

From D'Arcy J.M. Cain
Subject Re: Best way to index IP data?
Date
Msg-id 20080112010048.27678be8.darcy@druid.net
Whole thread Raw
In response to Re: Best way to index IP data?  (Greg Smith <gsmith@gregsmith.com>)
List pgsql-performance
On Fri, 11 Jan 2008 21:56:38 -0500 (EST)
Greg Smith <gsmith@gregsmith.com> wrote:
> On Fri, 11 Jan 2008, Steve Atkins wrote:
>
> > You may well need netmasks to configure your interface, but there's
> > absolutely no need for them to identify an IP endpoint, which is all you
> > need to identify the destination the packet is going to, and that is the
> > most common use of IP addresses.
>
> Technically you can't ever send a packet unless you know both the endpoint
> and your local netmask.  As the sender, you're obligated to determine if
> the destination is on your local LAN (in which case you send it there) or
> if it goes to the gateway.  That's similar to a routing decision, but it's
> not quite--if you don't have to look in a routing table, it's not actually
> part of routing.

Not sure what your point is here.  Sure, you need the netmask but not
of every IP address you send to, only for the IP/network that you are
on.  That's a grand total of one netmask per interface that you need to
know.  And you don't store it in your database.

--
D'Arcy J.M. Cain <darcy@druid.net>         |  Democracy is three wolves
http://www.druid.net/darcy/                |  and a sheep voting on
+1 416 425 1212     (DoD#0082)    (eNTP)   |  what's for dinner.

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