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Re: SPARQL-friendly alternative to rdf:Lists?

From: Antoine Zimmermann <antoine.zimmermann@emse.fr>
Date: Mon, 14 Oct 2013 17:00:13 +0200
Message-ID: <525C06FD.3010106@emse.fr>
To: semantic-web@w3.org
CC: david@dbooth.org
I suggest that you look at this answer by Joshua Taylor in Stackoverflow:

stackoverflow.com/questions/17523804/is-it-possible-to-get-the-position-of-an-element-in-an-rdf-collection-in-sparql/17530689#17530689


It shows a pure SPARQL 1.1 query that returns all the elements of a list 
ordered by their position in the list. Very nice trick.
However, it also shows that using this trick will blow up the execution 
time when the number of elements increase, and a customised programmatic 
solution is far more efficient in general.



AZ.





Le 11/10/2013 16:02, David Booth a écrit :
> rdf:Lists are notoriously difficult to use in SPARQL if one wishes to
> retain the *order* of the items in the list.  James Leigh and David Wood
> made a nice proposal a few years ago to address this problem directly at
> the RDF level,
> http://www.w3.org/2009/12/rdf-ws/papers/ws14
> but for whatever reasons, that work was not included in the charter of
> the current RDF working group.  As a result people often use some other
> means of representing ordered lists in RDF, such as by [item, index] pairs.
>
> For those who use an alternate way to represent an *ordered* list of
> items in RDF (instead of rdf:List), I am wondering:
>
> 1. What *ordered* list representation do you prefer, and why?
>
> 2. Have there been any efforts toward standardizing alternative
> *ordered* list representations in RDF?  E.g., has anyone written up a
> spec on how they prefer to do it?
>
> Thanks,
> David
>
>

-- 
Antoine Zimmermann
ISCOD / LSTI - Institut Henri Fayol
École Nationale Supérieure des Mines de Saint-Étienne
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Received on Monday, 14 October 2013 15:00:41 UTC

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