Re: Quorum commit for multiple synchronous replication.

On Thu, Aug 17, 2017 at 2:08 PM, Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> On Wed, Aug 16, 2017 at 4:37 PM, Michael Paquier
> <michael(dot)paquier(at)gmail(dot)com> wrote:
>> On Wed, Aug 16, 2017 at 4:24 PM, Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
>>> FWIW, in my opinion if tte current behavior of 'N(a,b)' could confuse
>>> users and we want to break the backward compatibility, I'd rather like
>>> to remove that style in PostgreSQL 10 and to raise an syntax error to
>>> user for more safety. Also, since the syntax 'a, b' might be opaque
>>> for new users who don't know the history of s_s_names syntax, we could
>>> unify its syntax to '[ANY|FIRST] N (a, b, ...)' syntax while keeping
>>> the '*'.
>>
>> I find the removal of a syntax in release N for something introduced
>> in release (N - 1) a bit hard to swallow from the user prospective.
>> What about just issuing a warning instead and say that the use of
>> ANY/FIRST is recommended? It costs nothing in maintenance to keep it
>> around.
>
> Yeah, I think that would be better. If we decide to not make quorum
> commit the default we can issue a warning in docs. Attached a draft
> patch.

I had in mind a ereport(WARNING) in create_syncrep_config. Extra
thoughts/opinions welcome.
--
Michael