Re: pg_system_identifier()

On Mon, Aug 26, 2013 at 7:47 AM, Jim Nasby <jim@nasby.net> wrote:
> On 8/23/13 11:23 AM, Greg Stark wrote:
>>
>> This doesn't generate a unique id. You could back up a standby and restore
>> it and point it at the original master and end up with two standbies with
>> the same id.
>
>
> If you want to enforce something unique throughout a cluster, I think we're
> stuck with having the cluster communicate IDs across an entire cluster.
> AFAIK that's how both Slony and londiste 3 do it.
The same applies to Postgres-XC for node identifiers. Users can adapt
the settings of their cluster to their own needs.

> I think it's also noteworthy that Slony and londiste both rely on the user
> specifying node identifiers. They don't try to be magic about it. I think
> there's 2 advantages there:
>
> - Code is simpler
> - Users can choose a naming schema that makes sense for them
Definitely agreed on that.
-- 
Michael