Re: oid's and primary keys on insert

On Sat, Aug 10, 2002 at 09:13:46AM +1200, Rob Brown-Bayliss wrote:
> So if all goes well, each morning each site will start with essentially
> identical databases. Many tables in the database refer to transactions
> specific to one site or another. The primary key on these tables are
> inserted via a trigger, and are in the form of "location-sequence" so
> that this 46-23456 represents the primary key for location 46, sequence
> 23456 on that machine.

Why don't you use a sequence at each site and a "site id" field?
Then put a unique index on the site id + the sequence. You'd get
something like

|site_id|trans_id|
------------------
| 46 | 23456 |

Also makes it easier to get "all transactions from site 46". You can
even set each site's site_id field to the appropriate default, if you
want, so that you don't have to handle it in your code.

> Doesnt' PostgreSQL use the OID's for it's own internal use? So that
> every item has a unique identifier for postgresql to play with, not
> necessarily the user)

No, every item doesn't need it. System things do. So tables are
identified by OID. But a field in a table is field n of table OIDnn.

A

--
----
Andrew Sullivan 87 Mowat Avenue
Liberty RMS Toronto, Ontario Canada
<andrew(at)libertyrms(dot)info> M6K 3E3
+1 416 646 3304 x110