Re: pg_system_identifier()

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
endup 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
IDsacross an entire cluster. AFAIK that's how both Slony and londiste 3 do it.
 

I think it's also noteworthy that Slony and londiste both rely on the user specifying node identifiers. They don't try
tobe magic about it. I think there's 2 advantages there:
 

- Code is simpler
- Users can choose a naming schema that makes sense for them
-- 
Jim C. Nasby, Data Architect                       jim@nasby.net
512.569.9461 (cell)                         http://jim.nasby.net