--- In firebird-support@yahoogroups.com, "David Johnson"
<d_johnson@c...> wrote:

>
> ----- Original Message -----
> From: Alan McDonald
> To: firebird-support@yahoogroups.com
> Sent: Sunday, May 23, 2004 6:21 PM
> Subject: RE: [firebird-support] Re: Primary Keys - [was] Database

File Size

>
>
> --- In firebird-support@yahoogroups.com, "Alan McDonald" wrote:
> > > But it says something to those who are using UUIDs as PKs -

thinking

> > that it
> > > gives them limitless keys for a 1000 years.
> >
> > The main attraction of UUIDS, is that they can be generated at
> > different sites without collision.
> >
>
> If you need to have the client create the PKs, that's true. But

for server

> created PKs, integers can provide uniqueness without collision

too. I am

> asked many times about this and in 99% of cases integers will do

the job

> withou problem for much more than 1000 years.
> Alan
>
> You are presuming that all database apps are client-server. There

are also distributed systems that can, by nature of their job, have no
centralized "server" that is common, but must depend on intermittent
merges for synchronization. Any database app that is used for data
gathering in a mobile environment, or any system that must be able to
function for prolonged periods in the absence of communications to a
"central" database.

Why not to build PKs like (Site_ID, Table_ID) in this case? This
not only provides uniqueness but advantages in further grouping and
identifiying "owner" of the record too.

Best regards,
Alexander.