Re: Re: BUG #13685: Archiving while idle every archive_timeout with wal_level hot_standby

On Wed, Feb 10, 2016 at 1:42 PM, Michael Paquier <michael(dot)paquier(at)gmail(dot)com>
wrote:
>
> On Wed, Feb 10, 2016 at 5:00 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
wrote:
> > Okay, but isn't it better that we remove the snapshot taken
> > at checkpoint time in the main branch or till where this code is
> > getting back-patched. Do you see any need of same after
> > having the logging of snapshot in bgwriter?
>
> But this one is necessary as well to allow hot standby faster to
> initialize, no? Particularly in the case where a bgwriter snapshot
> would have been taken just before the checkpoint, there may be up to
> 15s until the next one.
>

It could be helpful if checkpoint is done at shorter intervals, otherwise
we anyway log it at 15s interval and if need faster initialisation
of hot-standby, then it is better to reduce the log snapshot interval
in bgwriter. I think if go by my reasoning then it should have been
removed when bgwriter is changed to log snapshot, so I think you
can take this suggestion if you also feel the same, anyway this
is not a correctness issue.

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