Re: [HACKERS] Quorum commit for multiple synchronous replication.

On Tue, Apr 25, 2017 at 2:09 PM, Kyotaro HORIGUCHI
<horiguchi.kyotaro@lab.ntt.co.jp> wrote:
>
> I'm not good at composition, so I cannot insist on my
> proposal. For the convenience of others, here is the proposal
> from Fujii-san.
>

Do you see any problem with the below proposal?  To me, this sounds reasonable.

> +     A quorum-based synchronous replication is basically more efficient than
> +     a priority-based one when you specify multiple standbys in
> +     <varname>synchronous_standby_names</> and want to replicate
> +     the transactions to some of them synchronously. In this case,
> +     the transactions in a priority-based synchronous replication must wait for
> +     reply from the slowest standby in synchronous standbys chosen based on
> +     their priorities, and which may increase the transaction latencies.
> +     On the other hand, using a quorum-based synchronous replication may
> +     improve those latencies because it makes the transactions wait only for
> +     replies from the requested number of faster standbys in all the listed
> +     standbys, i.e., such slow standby doesn't block the transactions.
>

Can we do few modifications like:
improve those latencies --> reduce those latencies
such slow standby --> a slow standby

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com