Re: Unique cluster / instance identifier?

On 2/18/19 1:03 PM, Andrew Gierth wrote:
>>>>>> "S" == S Bob <sbob@quadratum-braccas.com> writes:
>
>  S> Hi all;
>
>  S> Does PostgreSQL store a unique cluster or instance identifier that
>  S> we can access to identify our instances?
>
> Yes. But it's not easy to get at: it's the "Database system identifier"
> shown in the output of pg_controldata. (pg12+ will have a function to
> get it from SQL, but released versions don't.)

Umm, that function has been there since pg 9.6

select left(version(),17), system_identifier from pg_control_system();
       left        |  system_identifier
-------------------+---------------------
 PostgreSQL 9.6.11 | 6320270156373568679
(1 row)

Joe

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