Re: Proposal: "Causal reads" mode for load balancing reads without stale data

On Mon, Feb 22, 2016 at 9:39 AM, Thom Brown <thom@linux.com> wrote:
> On 21 February 2016 at 23:18, Thomas Munro
> <thomas.munro@enterprisedb.com> wrote:
> The replay_lag is particularly cool.  Didn't think it was possible to
> glean this information on the primary, but the timings are correct in
> my tests.
>
> +1 for this patch.  Looks like this solves the problem that
> semi-synchronous replication tries to solve, although arguably in a
> more sensible way.

Yeah, having extra logic at application layer to check if a certain
LSN position has been applied or not is doable, but if we can avoid it
that's a clear plus.

This patch has no documentation. I will try to figure out by myself
how the new parameters interact with the rest of the syncrep code
while looking at it but if we want to move on to get something
committable for 9.6 it would be good to get some documentation soon.
-- 
Michael