Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> Tom Lane escribi�:
>> That particular ID would be a horrid choice, because we don't try very
>> hard to ensure it's unique. In particular, a standby server on the same
>> machine as the master (not an uncommon case, at least for testing
>> purposes) would be a guaranteed fail with that approach.
> I wonder if it would make sense to generate a unique name at some
> initial point in the history of the service (perhaps at initdb time, or
> at the first postmaster start) and store this name in a special,
> separate file in PGDATA. On subsequent starts we read the name from
> there and always use it consistently.
Meh --- that would have the same behavior as the system identifier,
ie it would propagate to slave servers without extraordinary (and
easily bypassed) measures to prevent it.
regards, tom lane