On Wed, Apr 20, 2005 at 12:30:08 +0800, "Ilya A. Kovalenko" <[EMAIL PROTECTED]> wrote: > GS> I see a use case for of generating addresses based on a sequence or some > GS> primary key from the database. > > GS> Something like > > GS> CREATE SEQUENCE hosts_ip_seq MAXVALUE 65536; > GS> ALTER TABLE hosts ALTER ip SET DEFAULT '10.0.0.0/16'::inet + > nextval(hosts_ip_seq') > > hmm, not quite good idea - SEQUENCEs, by design, does not rollback next > value on transation rollback, so you'll have holes on address range when > other values will break some constraints or concurrent sessions > appears.
You are going to have to have some way of handling holes anyway. What happens when an allocated IP address is returned? That is why I think for most uses a table with a row for each possible allocation is the way to go. ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
