[Standards] Exact hint for Result Set Management

Florian Schmaus flo at geekplace.eu
Wed Jul 11 17:25:24 UTC 2018

On 11.07.2018 18:01, Matthew Wild wrote:
> On 11 July 2018 at 16:33, Florian Schmaus <flo at geekplace.eu> wrote:
>> I recently submitted PR #672 to the xeps repo
>> https://github.com/xsf/xeps/pull/672
>> to make users of RSM, like MAM, aware whether the result is exact or
>> not. It received some scepticism from the council members in today's
>> council meeting. I am to blame here as I thought the abstract motivation
>> in the commit message was enough. It appears it wasn't.
>> While I think multiple applications could exploit that information, my
>> particular motivation was MAM. Consider the scenario where you have a
>> master archive and a local archive. The local archive may have multiple
>> holes at unknown locations. Now you want to sync your local archive from
>> the master using MAM/RSM.
> I'm not keen on this solution for the premise you've given.
> I don't believe that when using MAM correctly you would ever end up
> with "holes at unknown locations" in your local archive. I don't think
> that encouraging people to use a "bisection algorithm" is the right
> thing to do.

So you don't want MAM users to be able to efficiently sync archives with
multiple holes by a simple change because you do not want MAM to be used
in scenarios where this could happen?

Even if we would live in a world where such MAM archives are never going
to happen, adding the exact hint to RSM is worthwhile.

From a generic, non MAM-specific point-of-view, RSM is eventually used
to sync data, and for that you often want to now if the RSM metadata is
exact or not. My MAM example is just one illustration of that. It always
appeared like an afterthought that RSM does not allow the RSM data
originator to signal if the numbers are exact or not. The proposed
change tries to fix that.

- Florian

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 618 bytes
Desc: OpenPGP digital signature
URL: <http://mail.jabber.org/pipermail/standards/attachments/20180711/c7f3eba4/attachment.sig>

More information about the Standards mailing list