Ashwin Agrawal <aagrawal(at)pivotal(dot)io> writes:
> Okay just bouncing another approach, how about generating UUID for a
> postgres instance during initdb and pg_basebackup ?
There's no uuid generation code in core postgres, for excellent reasons
(lack of portability and lack of failure modes are the main objections).
This is not different in any meaningful way from the proposal to use
timestamps, except for being more complicated.
regards, tom lane