Re: pg_system_identifier()

On 08/22/2013 02:51 PM, Fujii Masao wrote:
> On Thu, Aug 22, 2013 at 6:43 AM, Vik Fearing <vik.fearing@dalibo.com> wrote:
>> After someone in IRC asked if there was an equivalent to MySQL's
>> server_id, it was noted that we do have a system identifier but it's not
>> very accessible.
>>
>> The attached patch implements a pg_system_identifier() function that
>> exposes it.
> What's the use case?

It's information about the server that's only accessible through
pg_controldata.  I don't know if that's justification enough, which is
why I didn't add it to the commitfest yet.

> IIUC, PostgreSQL's system identifier is not equal to MySQL server-id.
> In PostgreSQL, in replication, the master and all the standbys must
> have the same system identifier. OTOH, in MySQL, they have the different
> server-ids. No?

I have zero experience with MySQL.

-- 
Vik