Re: Salmon Protocol for automatic RDF store augmentation?

On 29 January 2010 12:48, Danny Ayers <danny.ayers@gmail.com> wrote:

> After seeing reference to it on the Social Web XG list, I've just been
> reading about the cutely-named Salmon Protocol (summary at [1]) which
> is primarily intended for use around syndication feeds, passing
> downstream comments, ratings, and  annotations back to the originating
> publisher.
>
> Thinking out loud, it seems like there could be a handy use for it in
> data sharing, in effect:
>
> * store A broadcasts it has some information about resource R
> * store B receives the announcement, discovers it has additional
> information about R
> * store B passes that information back to store A
>
> Suppose we have a triplestore which publishes a recent-additions feed
> (Atom with an RDF payload) as well as a Salmon Protocol endpoint.
> These could presumably be implemented as thin wrappers around a
> SPARQL/SPARQL Update endpoint.
>
> We also have a subscriber to the recent-additions feed, which also has
> a triplestore.
>
> Now say the publisher passes along a triple, for example:
>
> <http://example.org/fred#me> a foaf:Person .
>
> The subscriber receives this and runs a query like:
>
> CONSTRUCT { ?s ?p ?o }
> WHERE { <http://example.org/fred#me> ?p ?o }
>
> - and posts the results back to the original publisher, which adds
> those triples to its store.
>
> While I'm sure it would be possible to do this kind of thing more
> directly using the semweb stack, use of the Salmon Protocol could
> offer hooks into more traditional content-oriented Atom
> datasources/sinks. (Noting that Atom can be mapped to RDF).
>
> Does that make any sense?
>

Yes,

Also thinking out loud, I wonder if it would be possible to make it realtime
and pass only change sets (SPARQL Updates?) or maybe a timestamp/hash to see
if your version (of the specific data set you are interested in) is out of
date?  Then you could work on a "sync or update" style protocol, and aim to
send differences only, where possible.


>
> Cheers,
> Danny.
>
> [1] http://www.salmon-protocol.org/salmon-protocol-summary
>
> --
> http://danny.ayers.name
>
>