Null pointer exception for query

[Andy]

A null pointer exception occurs with Anzo nightly build 2009-07-27
when you issue a describe query from the command line:

anzo query "DESCRIBE <http://example.org/person/1>"

[Lee Feigenbaum]

Open Anzo does not yet support SPARQL DESCRIBE queries, though it is a
bug that the result is an NPE.

We've considered various designs for DESCRIBE X implementations, ranging
from:

* X ?p ?o
* X ?p ?o UNION ?s ?p X
* concise bounded description of X
* contents of named graph X
* minimum spanning graphs

We've also considered extending DESCRIBE to allow an algorithm to be
explicitly given and looked up in a registry.

To help inform future design & implementation of DESCRIBE, can you let
us know which of these meets your use case needs?

If anyone else has an opinion, please share it as well.

thanks,
Lee

>
>
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--
Lee Feigenbaum
VP Technology & Standards, Cambridge Semantics Inc
l...@cambridgesemantics.com
1-617-553-1060

[Andy]

X ?p ?o UNION ?s ?p X

that is found in *any* graph.

On Jul 31, 2:19 pm, Lee Feigenbaum <l...@cambridgesemantics.com>
wrote:

[Lee Feigenbaum]

Andy wrote:
> X ?p ?o UNION ?s ?p X
>
> that is found in *any* graph.

Can you please elaborate on your use case? My general inclination is
that DESCRIBE should perform an operation that is not so easily encoded
in a standard SPARQL SELECT query. (Hence my personal preference tends
to be for CBDs.)

Lee