Re: Support for N synchronous standby servers - take 2

On Sat, May 16, 2015 at 5:58 PM, Sawada Masahiko wrote:
> The dedicated language for multiple sync replication would be more
> extensibility as you said, but I think there are not a lot of user who
> want to or should use this.
> IMHO such a dedicated extensible feature could be extension module,
> i.g. contrib. And we could implement more simpler feature into
> PostgreSQL core with some restriction.

As proposed, this feature does not bring us really closer to quorum
commit, and AFAIK this is what we are more or less aiming at recalling
previous discussions. Particularly with the syntax proposed above, it
is not possible to do some OR conditions on subgroups of nodes, the
list of nodes is forcibly using AND because it is necessary to wait
for all the subgroups. Also, users may want to track nodes from the
same group with different application_name.
--
Michael