Re: pg_system_identifier()

On Thu, Aug 22, 2013 at 06:18:39PM +0200, Andres Freund wrote:
> But essentially we already have something like that by the combination
> of system identifier and timeline id. Admittedly there's the weakness
> that the timelineid can increase the same on several machines in the
> cluster but that's a weakness we ought to fix sometime independent of
> this.
> 
> So maybe the answer is to also expose the current timeline?
> 
> An alternative would be to have a pg_controldata_values() SRF...

It seems the value is more of a _cluster_ identifier than a system
identifier.  We don't allow cross-major-version replication, so I am
confused why we can't rename it in 9.4.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + It's impossible for everything to be true. +