[redland-dev] problem using model with virtuoso storage backend

[Jasper Op de Coul]

Hi

I've been experimenting with the Virtuoso storage backend through the 
python bindings. I ran into some problems I would like to share.

With the python bindings you can query the backend using either:

query.execute(model) or model.execute(query)

this translates to librdf_query_execute and librdf_model_query_execute 
in the c code. A Segmentation fault occurs when using 
librdf_query_execute with the 'vsparql' language, the 
librdf_model_query_execute function works fine though.

Another problem I ran into is that the add_statement functions on a 
model will assume that the object part of the statement is a resource 
uri if there is no language or datatype specified.

This also happens when you parse directly into a model:

data = '<x:test> <x:label> "test".\n'
parser = RDF.Parser("ntriples")
parser.parse_string_into_model(model, data, RDF.Uri('file://'))
for stat in model: print stat

prints:

<x:test> <x:label> <test>

(adding a language or datatype to the literal triggers the right behaviour)

When I upload data using the rdfproc utility everything works fine,
so it seems the problem is tied up with the model code somehow.


I'm using:

redland-1.0.11
redland-bindings-1.0.11.1
virtuoso-opensource-6.1.2

All tests of the `redland-virtuoso-test` passed.

Thanks,

Jasper Op de Coul


-- 
Jasper Op de Coul -- Erasmus University Rotterdam
t +31 10 4082871  -- http://eur.nl/ub
Burgemeester Oudlaan 50 3062 PA Rotterdam -- The Netherlands
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