My plan is to start with a Graph implementation. We expect to write 3 tables: SPO, POS, OPS (I think). Currently we don't have an easy way to handle find( ANY, ANY, ANY) so I suspect we will just start with permitting a column scan on Cassandra.
I have not looked at DynamoDB but as I recall there are significant differences under the hood. I expect that we will move on to a custom model or query engine to get the best performance but that is not what we are planning for the first cut. I am still waiting for management approval to do this at work .... sometimes it takes longer to get the paperwork done than it does to design the thing. Claude On Mon, Oct 17, 2016 at 6:39 PM, Paul Houle <paul.ho...@ontology2.com> wrote: > I like DynamoDB as a target for this sort of thing. There are many > tasks which are small-scale yet critical where it would otherwise be > hard to provide a distributed and reliable database. Put that together > with Lambda, which does the same for computation, and you are cooking > with gas. > > I wrote a 1-1 translation of DynamoDB documents to RDF that I use > throughout an application; the code is DynamoDB idiomatic in every way, > just the application reads and writes (a constrained set of) RDF > documents. > > Right now I dump the documents from the DynamoDB system into a triple > store when I want a panoptic view, but with a distributed graph like > that would mean being able to run SPARQL queries against DynamoDB > directly. > > There are many products in the same family as Cassandra and DynamoDB and > it would be good to think through the math so we can approach them all > in a similar way. > > -- > Paul Houle > paul.ho...@ontology2.com > > On Mon, Oct 17, 2016, at 12:31 PM, A. Soroka wrote: > > Yep, > > > > http://iswc2011.semanticweb.org/fileadmin/iswc/Papers/ > Workshops/SSWS/Ladwig-et-all-SSWS2011.pdf > > > > indicates that they are indexing by subject. As someone who has > > implemented LDP, that is definitely the approach that makes sense there. > > > > --- > > A. Soroka > > The University of Virginia Library > > > > > On Oct 17, 2016, at 12:20 PM, Andy Seaborne <a...@apache.org> wrote: > > > > > > IIRC It stores CBDs indexed by subject so it is the "other" model to > Rya. Better for LDP (??). > > > > > > Andy > > > > > > On 17/10/16 15:41, A. Soroka wrote: > > >> There's also: > > >> > > >> https://github.com/cumulusrdf/cumulusrdf > > >> > > >> in a similar vein (RDF over Cassandra). Not sure what kind of > particular uses it expects to support. > > >> > > >> --- > > >> A. Soroka > > >> The University of Virginia Library > > >> > > >>> On Oct 17, 2016, at 7:02 AM, Andy Seaborne <a...@apache.org> wrote: > > >>> > > >>> Hi Claude, > > >>> > > >>> There is certainly interest from me. > > >>> > > >>> What the best thing to do depends on various factors. By putting it > in extras I presume you mean it gets added to the release? That is not the > only way forward. > > >>> > > >>> An important aspect of Apache is "Community over code" - will there > be a community around this code? Is that community the same, or > significant overlap, as the Jena community? > > >>> > > >>> There are various reasons for wanting RDF over a column store - > which use cases are the most important for this work? > > >>> > > >>> They lead to different ways of using Cassandra. For example, > Rya(incubating) uses Accumulo tables as indexes, and partial scans of the > table is streaming. Other systems try to use the columns for properties, > possibly more useful for LDP style than SPARQL. > > >>> > > >>> Andy > > >>> > > >>> On 15/10/16 18:38, Claude Warren wrote: > > >>>> Howdy, > > >>>> > > >>>> We have a project at work that is implementing Jena Graph on > Cassandra. I > > >>>> am wondering if there is enough interest here to accept it as a > > >>>> contribution. I was thinking that it might fit in the Extras > category. > > >>>> > > >>>> I can not promise release of the code yet as I have to present it > to our > > >>>> internal Intellectual Property group first. > > >>>> > > >>>> Thoughts? > > >>>> > > >>>> Claude > > >>>> > > >> > > > -- I like: Like Like - The likeliest place on the web <http://like-like.xenei.com> LinkedIn: http://www.linkedin.com/in/claudewarren
