[redland-dev] triples with context

[Dave Beckett]

Eyal Oren wrote:
> Hi,
> 
> I am using triples with context (each triple has a context denoting its 
> provenance).  That works.  I need to persistently store/retrieve them.  
> Serialising them to xml or ntriples means losing the context, so that is 
> no option.

Yes.  redland (via raptor) provides no serialised forms that record 
redland contexts in a syntax.

> Therefore I'm trying to use a hash_store (without serialising to 
> ntriples or xml). First run: I create a model with a hash store and add 
> some triples to it. Second run, I read from the earlier hash store, but 
> if I associate a model with that hash_store it is empty.

That's strange.  As long as you open the second store with model options 
contexts='yes', it should find the contexts.  You pretty much have to 
have the identical storage options for re/opening a model.   However 
what you say suggest you have option new='yes' which will zero any 
existing model on opening.

> Is what I want possible: persistently storing triples without 
> serialising them?  Or some other way of persistently storing triples 
> with context?

It is possible.

If the storage options aren't the problem, maybe you can provide a 
minimal test case that demonstrates it with a triple or two.

Dave