Re: Multiple Named Graph

On 21 Mar 2014, at 09:39, Reto Gmür wrote:
> Hi Henry,
> 
> On Fri, Mar 21, 2014 at 12:27 AM, henry.story@bblfish.net <henry.story@bblfish.net> wrote: 
>> With the previous published version it was possible to have an LDP compliant server backed by a single graph. This would be my choice of implementation if the data has a single provenance and the access restrictions are the same for all the triples.
> 
> I think you can do that with a DirectContainer. You can put your ldp:contains and all the rest of your triples in the same graph.
> 
> That's not the point. It's not about being able to put all in the same graph is LDP is designed to be backed by different graphs of different LDPR. Assume are are running a bank. Several years ago we replaced our RDBMS with a triple store. We are having one graph containing all the customers, as well as their assets and liabilities we manage (we discussed a lot about which design to choose and this turned out to be the best). Allowing our data to be accessed via LDP should not require us to split out data into many graphs.

So, I agree with this. Henry refers to "vanishingly small" circumstances, but, I don't see it this way. I think it is very natural that a triple store would be deployed pretty much in the same way as a RDBMS, and would expect this would a very common scenario. As LDP concerns the client-server protocol, I would expect that the server would do some partitioning of the data in the store. 

Roger


>  
> Some people fought very hard for what seems on the whole like a pretty bad idea. The circumstances under which that may be a good idea is vanishingly small.
> 

> Not sure what idea you're referring to. Also a pointer to these "fights" would be useful.
> 
> Cheers,
> Reto
>  
> 
>> This change in the new version seems however to mandate implementation to be based on different graphs for the different resources. 
>> 
>> In my opinion this is a significant loss of flexibility. I would like for simple implementations based on one graph to be possible. It can also be useful for an implementation to be based on multiple graphs representing different provenances or confidentiality but containing descriptions of larger and possibly overlapping sets of resources. With the latter approach the resource description accessed through LDP would contain more or less triples depending on my access rights and the sources I've decided to trust.
>> 
>> Cheers,
>> Reto  
>> 
> 
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