Re: deterministic naming of blank nodes

On 05/20/2015 07:08 PM, Gregg Kellogg wrote:
>> On May 20, 2015, at 2:55 PM, David Booth <> wrote:
>> [ . . . ] currently there
>> is no standard way to directly refer to a bnode from a separate
>> SPARQL operation.  This is a known problem already with SPARQL,
>> which causes grief when doing followup queries.  But if SPARQL
>> servers were enhanced to (optionally) enable subsequent queries or
>> update operations to refer directly to blank nodes by their
>> *original* labels, then both PATCH and followup queries would work
>> on SPARQL servers.  (In the case of implicit bnodes generated by
>> Turtle/SPARQL [] or () notation the server would assign an original
>> label.)  This seems like a good route to take, though it means
>> adding that feature to SPARQL.  I'll send this to the SPARQL list
>> to see what
>> others there think.
> This might only work on SPARQL servers that are capable of
> “remembering” original identifiers, and can rapidly get out of sync
> as the dataset changes.

I don't think it would have to get out of sync any more than URIs get 
out of sync.  The servers would have to remember them, just as they 
remember URIs.

> Alternatively, some SPARQL servers may use
> stable internal identifiers that could serve this purpose (still
> requiring normative normalization), but I suspect that there are some
> implementations that don’t guarantee such stable identifiers).

Right, it would involve enhancing SPARQL servers.

David Booth

Received on Thursday, 21 May 2015 02:27:27 UTC