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Re: major open issues SPARQL Update

From: Axel Polleres <axel.polleres@deri.org>
Date: Tue, 26 Apr 2011 14:41:23 +0100
Cc: SPARQL Working Group <public-rdf-dawg@w3.org>
Message-Id: <FEEFE44E-AE8B-4AE8-877E-36F8355D3EDB@deri.org>
To: Axel Polleres <axel.polleres@deri.org>
One more I forgot in the context of 1) (can be considered a subissue of 1):

 Do we need USING DEFAULT ?

i.e. what if I want to create a dataset where I want to merge the default grpah with some named graph?

A general question behind this is IMO: 
 - Do we understand USING/USING NAMED as referring to graphs in the graph store or externally retrieved graphs like with LOAD?
 - Do we  - implementation-dependent - want to allow for both or fix that?

Axel
 
On 26 Apr 2011, at 14:31, Axel Polleres wrote:

> I have to go through the "Open" points from the reviews again once more, 
> but I see overall four *major* open issues for Update before we can go to LC:
> 
> 
> 1) semantics of USING, see also the example I put on 
>      http://www.w3.org/2009/sparql/wiki/To_Last_Call#WG_issues_.26_needed_decisions_2
>   USING is the same as FROM, i.e. it allows to explicitly declare a (NEW?) dataset with (NEW?) bnodes.
>   how USING/FROM is retrieving constructing that dataset is probably something where we have one coin flip decision to make still:
>        a) we prescribe that bnodes in an explicitly declared dataset must be disjoint from the grahp store
>        b) we leave that up to the implementation
> 
> When I discussed this with Paul, we came to the following conclusion:  
>       a) would mean identical to FROM, 
>       b) would leave some more freedom to preserve bnodes.
> 
> 2) Need to bridge from Syntax to semantics 
> 
> That is, how do we get from an Update request to the respective "update Operation call"?
> I have the following in mind here for each of the subsections of section 4.3:
>    - We copy in essence the syntax snippets from Section 3 to section 4 and state how they map to the respective Update Operation call
> 
> 3) Need to define UpdateRequest as a sequence of UpdateOperations in the formal semantics section... 
>    I'd be grateful for ideas how to tackle that...
> 
> 4) blank nodes in QuadPattern aren't mentioned explicitly in OpDeleteInsert - I think that might need attention
> 
> 
> Axel
Received on Tuesday, 26 April 2011 13:41:51 GMT

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